net/sched/cls_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_api.c  Packet classifier API.
   4  *
   5  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6  *
   7  * Changes:
   8  *
   9  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/slab.h>
  22 #include <linux/idr.h>
  23 #include <linux/jhash.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rhashtable.h>
  26 #include <net/net_namespace.h>
  27 #include <net/sock.h>
  28 #include <net/netlink.h>
  29 #include <net/pkt_sched.h>
  30 #include <net/pkt_cls.h>
  31 #include <net/tc_act/tc_pedit.h>
  32 #include <net/tc_act/tc_mirred.h>
  33 #include <net/tc_act/tc_vlan.h>
  34 #include <net/tc_act/tc_tunnel_key.h>
  35 #include <net/tc_act/tc_csum.h>
  36 #include <net/tc_act/tc_gact.h>
  37 #include <net/tc_act/tc_police.h>
  38 #include <net/tc_act/tc_sample.h>
  39 #include <net/tc_act/tc_skbedit.h>
  40 #include <net/tc_act/tc_ct.h>
  41 #include <net/tc_act/tc_mpls.h>
  42 #include <net/tc_act/tc_gate.h>
  43 #include <net/flow_offload.h>
  44 #include <net/tc_wrapper.h>
  45
  46 /* The list of all installed classifier types */
  47 static LIST_HEAD(tcf_proto_base);
  48
  49 /* Protects list of registered TC modules. It is pure SMP lock. */
  50 static DEFINE_RWLOCK(cls_mod_lock);
  51
  52 static struct xarray tcf_exts_miss_cookies_xa;
  53 struct tcf_exts_miss_cookie_node {
  54         const struct tcf_chain *chain;
  55         const struct tcf_proto *tp;
  56         const struct tcf_exts *exts;
  57         u32 chain_index;
  58         u32 tp_prio;
  59         u32 handle;
  60         u32 miss_cookie_base;
  61         struct rcu_head rcu;
  62 };
  63
  64 /* Each tc action entry cookie will be comprised of 32bit miss_cookie_base +
  65  * action index in the exts tc actions array.
  66  */
  67 union tcf_exts_miss_cookie {
  68         struct {
  69                 u32 miss_cookie_base;
  70                 u32 act_index;
  71         };
  72         u64 miss_cookie;
  73 };
  74
  75 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
  76 static int
  77 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
  78                                 u32 handle)
  79 {
  80         struct tcf_exts_miss_cookie_node *n;
  81         static u32 next;
  82         int err;
  83
  84         if (WARN_ON(!handle || !tp->ops->get_exts))
  85                 return -EINVAL;
  86
  87         n = kzalloc(sizeof(*n), GFP_KERNEL);
  88         if (!n)
  89                 return -ENOMEM;
  90
  91         n->chain_index = tp->chain->index;
  92         n->chain = tp->chain;
  93         n->tp_prio = tp->prio;
  94         n->tp = tp;
  95         n->exts = exts;
  96         n->handle = handle;
  97
  98         err = xa_alloc_cyclic(&tcf_exts_miss_cookies_xa, &n->miss_cookie_base,
  99                               n, xa_limit_32b, &next, GFP_KERNEL);
 100         if (err)
 101                 goto err_xa_alloc;
 102
 103         exts->miss_cookie_node = n;
 104         return 0;
 105
 106 err_xa_alloc:
 107         kfree(n);
 108         return err;
 109 }
 110
 111 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 112 {
 113         struct tcf_exts_miss_cookie_node *n;
 114
 115         if (!exts->miss_cookie_node)
 116                 return;
 117
 118         n = exts->miss_cookie_node;
 119         xa_erase(&tcf_exts_miss_cookies_xa, n->miss_cookie_base);
 120         kfree_rcu(n, rcu);
 121 }
 122
 123 static struct tcf_exts_miss_cookie_node *
 124 tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
 125 {
 126         union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
 127
 128         *act_index = mc.act_index;
 129         return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
 130 }
 131 #else /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 132 static int
 133 tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
 134                                 u32 handle)
 135 {
 136         return 0;
 137 }
 138
 139 static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
 140 {
 141 }
 142 #endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
 143
 144 static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
 145 {
 146         union tcf_exts_miss_cookie mc = { .act_index = act_index, };
 147
 148         if (!miss_cookie_base)
 149                 return 0;
 150
 151         mc.miss_cookie_base = miss_cookie_base;
 152         return mc.miss_cookie;
 153 }
 154
 155 #ifdef CONFIG_NET_CLS_ACT
 156 DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
 157 EXPORT_SYMBOL(tc_skb_ext_tc);
 158
 159 void tc_skb_ext_tc_enable(void)
 160 {
 161         static_branch_inc(&tc_skb_ext_tc);
 162 }
 163 EXPORT_SYMBOL(tc_skb_ext_tc_enable);
 164
 165 void tc_skb_ext_tc_disable(void)
 166 {
 167         static_branch_dec(&tc_skb_ext_tc);
 168 }
 169 EXPORT_SYMBOL(tc_skb_ext_tc_disable);
 170 #endif
 171
 172 static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
 173 {
 174         return jhash_3words(tp->chain->index, tp->prio,
 175                             (__force __u32)tp->protocol, 0);
 176 }
 177
 178 static void tcf_proto_signal_destroying(struct tcf_chain *chain,
 179                                         struct tcf_proto *tp)
 180 {
 181         struct tcf_block *block = chain->block;
 182
 183         mutex_lock(&block->proto_destroy_lock);
 184         hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
 185                      destroy_obj_hashfn(tp));
 186         mutex_unlock(&block->proto_destroy_lock);
 187 }
 188
 189 static bool tcf_proto_cmp(const struct tcf_proto *tp1,
 190                           const struct tcf_proto *tp2)
 191 {
 192         return tp1->chain->index == tp2->chain->index &&
 193                tp1->prio == tp2->prio &&
 194                tp1->protocol == tp2->protocol;
 195 }
 196
 197 static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
 198                                         struct tcf_proto *tp)
 199 {
 200         u32 hash = destroy_obj_hashfn(tp);
 201         struct tcf_proto *iter;
 202         bool found = false;
 203
 204         rcu_read_lock();
 205         hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
 206                                    destroy_ht_node, hash) {
 207                 if (tcf_proto_cmp(tp, iter)) {
 208                         found = true;
 209                         break;
 210                 }
 211         }
 212         rcu_read_unlock();
 213
 214         return found;
 215 }
 216
 217 static void
 218 tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
 219 {
 220         struct tcf_block *block = chain->block;
 221
 222         mutex_lock(&block->proto_destroy_lock);
 223         if (hash_hashed(&tp->destroy_ht_node))
 224                 hash_del_rcu(&tp->destroy_ht_node);
 225         mutex_unlock(&block->proto_destroy_lock);
 226 }
 227
 228 /* Find classifier type by string name */
 229
 230 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 231 {
 232         const struct tcf_proto_ops *t, *res = NULL;
 233
 234         if (kind) {
 235                 read_lock(&cls_mod_lock);
 236                 list_for_each_entry(t, &tcf_proto_base, head) {
 237                         if (strcmp(kind, t->kind) == 0) {
 238                                 if (try_module_get(t->owner))
 239                                         res = t;
 240                                 break;
 241                         }
 242                 }
 243                 read_unlock(&cls_mod_lock);
 244         }
 245         return res;
 246 }
 247
 248 static const struct tcf_proto_ops *
 249 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
 250                      struct netlink_ext_ack *extack)
 251 {
 252         const struct tcf_proto_ops *ops;
 253
 254         ops = __tcf_proto_lookup_ops(kind);
 255         if (ops)
 256                 return ops;
 257 #ifdef CONFIG_MODULES
 258         if (rtnl_held)
 259                 rtnl_unlock();
 260         request_module("cls_%s", kind);
 261         if (rtnl_held)
 262                 rtnl_lock();
 263         ops = __tcf_proto_lookup_ops(kind);
 264         /* We dropped the RTNL semaphore in order to perform
 265          * the module load. So, even if we succeeded in loading
 266          * the module we have to replay the request. We indicate
 267          * this using -EAGAIN.
 268          */
 269         if (ops) {
 270                 module_put(ops->owner);
 271                 return ERR_PTR(-EAGAIN);
 272         }
 273 #endif
 274         NL_SET_ERR_MSG(extack, "TC classifier not found");
 275         return ERR_PTR(-ENOENT);
 276 }
 277
 278 /* Register(unregister) new classifier type */
 279
 280 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
 281 {
 282         struct tcf_proto_ops *t;
 283         int rc = -EEXIST;
 284
 285         write_lock(&cls_mod_lock);
 286         list_for_each_entry(t, &tcf_proto_base, head)
 287                 if (!strcmp(ops->kind, t->kind))
 288                         goto out;
 289
 290         list_add_tail(&ops->head, &tcf_proto_base);
 291         rc = 0;
 292 out:
 293         write_unlock(&cls_mod_lock);
 294         return rc;
 295 }
 296 EXPORT_SYMBOL(register_tcf_proto_ops);
 297
 298 static struct workqueue_struct *tc_filter_wq;
 299
 300 void unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 301 {
 302         struct tcf_proto_ops *t;
 303         int rc = -ENOENT;
 304
 305         /* Wait for outstanding call_rcu()s, if any, from a
 306          * tcf_proto_ops's destroy() handler.
 307          */
 308         rcu_barrier();
 309         flush_workqueue(tc_filter_wq);
 310
 311         write_lock(&cls_mod_lock);
 312         list_for_each_entry(t, &tcf_proto_base, head) {
 313                 if (t == ops) {
 314                         list_del(&t->head);
 315                         rc = 0;
 316                         break;
 317                 }
 318         }
 319         write_unlock(&cls_mod_lock);
 320
 321         WARN(rc, "unregister tc filter kind(%s) failed %d\n", ops->kind, rc);
 322 }
 323 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 324
 325 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 326 {
 327         INIT_RCU_WORK(rwork, func);
 328         return queue_rcu_work(tc_filter_wq, rwork);
 329 }
 330 EXPORT_SYMBOL(tcf_queue_work);
 331
 332 /* Select new prio value from the range, managed by kernel. */
 333
 334 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 335 {
 336         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 337
 338         if (tp)
 339                 first = tp->prio - 1;
 340
 341         return TC_H_MAJ(first);
 342 }
 343
 344 static bool tcf_proto_check_kind(struct nlattr *kind, char *name)
 345 {
 346         if (kind)
 347                 return nla_strscpy(name, kind, IFNAMSIZ) < 0;
 348         memset(name, 0, IFNAMSIZ);
 349         return false;
 350 }
 351
 352 static bool tcf_proto_is_unlocked(const char *kind)
 353 {
 354         const struct tcf_proto_ops *ops;
 355         bool ret;
 356
 357         if (strlen(kind) == 0)
 358                 return false;
 359
 360         ops = tcf_proto_lookup_ops(kind, false, NULL);
 361         /* On error return false to take rtnl lock. Proto lookup/create
 362          * functions will perform lookup again and properly handle errors.
 363          */
 364         if (IS_ERR(ops))
 365                 return false;
 366
 367         ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
 368         module_put(ops->owner);
 369         return ret;
 370 }
 371
 372 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 373                                           u32 prio, struct tcf_chain *chain,
 374                                           bool rtnl_held,
 375                                           struct netlink_ext_ack *extack)
 376 {
 377         struct tcf_proto *tp;
 378         int err;
 379
 380         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 381         if (!tp)
 382                 return ERR_PTR(-ENOBUFS);
 383
 384         tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 385         if (IS_ERR(tp->ops)) {
 386                 err = PTR_ERR(tp->ops);
 387                 goto errout;
 388         }
 389         tp->classify = tp->ops->classify;
 390         tp->protocol = protocol;
 391         tp->prio = prio;
 392         tp->chain = chain;
 393         spin_lock_init(&tp->lock);
 394         refcount_set(&tp->refcnt, 1);
 395
 396         err = tp->ops->init(tp);
 397         if (err) {
 398                 module_put(tp->ops->owner);
 399                 goto errout;
 400         }
 401         return tp;
 402
 403 errout:
 404         kfree(tp);
 405         return ERR_PTR(err);
 406 }
 407
 408 static void tcf_proto_get(struct tcf_proto *tp)
 409 {
 410         refcount_inc(&tp->refcnt);
 411 }
 412
 413 static void tcf_chain_put(struct tcf_chain *chain);
 414
 415 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 416                               bool sig_destroy, struct netlink_ext_ack *extack)
 417 {
 418         tp->ops->destroy(tp, rtnl_held, extack);
 419         if (sig_destroy)
 420                 tcf_proto_signal_destroyed(tp->chain, tp);
 421         tcf_chain_put(tp->chain);
 422         module_put(tp->ops->owner);
 423         kfree_rcu(tp, rcu);
 424 }
 425
 426 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 427                           struct netlink_ext_ack *extack)
 428 {
 429         if (refcount_dec_and_test(&tp->refcnt))
 430                 tcf_proto_destroy(tp, rtnl_held, true, extack);
 431 }
 432
 433 static bool tcf_proto_check_delete(struct tcf_proto *tp)
 434 {
 435         if (tp->ops->delete_empty)
 436                 return tp->ops->delete_empty(tp);
 437
 438         tp->deleting = true;
 439         return tp->deleting;
 440 }
 441
 442 static void tcf_proto_mark_delete(struct tcf_proto *tp)
 443 {
 444         spin_lock(&tp->lock);
 445         tp->deleting = true;
 446         spin_unlock(&tp->lock);
 447 }
 448
 449 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
 450 {
 451         bool deleting;
 452
 453         spin_lock(&tp->lock);
 454         deleting = tp->deleting;
 455         spin_unlock(&tp->lock);
 456
 457         return deleting;
 458 }
 459
 460 #define ASSERT_BLOCK_LOCKED(block)                                      \
 461         lockdep_assert_held(&(block)->lock)
 462
 463 struct tcf_filter_chain_list_item {
 464         struct list_head list;
 465         tcf_chain_head_change_t *chain_head_change;
 466         void *chain_head_change_priv;
 467 };
 468
 469 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 470                                           u32 chain_index)
 471 {
 472         struct tcf_chain *chain;
 473
 474         ASSERT_BLOCK_LOCKED(block);
 475
 476         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 477         if (!chain)
 478                 return NULL;
 479         list_add_tail_rcu(&chain->list, &block->chain_list);
 480         mutex_init(&chain->filter_chain_lock);
 481         chain->block = block;
 482         chain->index = chain_index;
 483         chain->refcnt = 1;
 484         if (!chain->index)
 485                 block->chain0.chain = chain;
 486         return chain;
 487 }
 488
 489 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 490                                        struct tcf_proto *tp_head)
 491 {
 492         if (item->chain_head_change)
 493                 item->chain_head_change(tp_head, item->chain_head_change_priv);
 494 }
 495
 496 static void tcf_chain0_head_change(struct tcf_chain *chain,
 497                                    struct tcf_proto *tp_head)
 498 {
 499         struct tcf_filter_chain_list_item *item;
 500         struct tcf_block *block = chain->block;
 501
 502         if (chain->index)
 503                 return;
 504
 505         mutex_lock(&block->lock);
 506         list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 507                 tcf_chain_head_change_item(item, tp_head);
 508         mutex_unlock(&block->lock);
 509 }
 510
 511 /* Returns true if block can be safely freed. */
 512
 513 static bool tcf_chain_detach(struct tcf_chain *chain)
 514 {
 515         struct tcf_block *block = chain->block;
 516
 517         ASSERT_BLOCK_LOCKED(block);
 518
 519         list_del_rcu(&chain->list);
 520         if (!chain->index)
 521                 block->chain0.chain = NULL;
 522
 523         if (list_empty(&block->chain_list) &&
 524             refcount_read(&block->refcnt) == 0)
 525                 return true;
 526
 527         return false;
 528 }
 529
 530 static void tcf_block_destroy(struct tcf_block *block)
 531 {
 532         mutex_destroy(&block->lock);
 533         mutex_destroy(&block->proto_destroy_lock);
 534         xa_destroy(&block->ports);
 535         kfree_rcu(block, rcu);
 536 }
 537
 538 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 539 {
 540         struct tcf_block *block = chain->block;
 541
 542         mutex_destroy(&chain->filter_chain_lock);
 543         kfree_rcu(chain, rcu);
 544         if (free_block)
 545                 tcf_block_destroy(block);
 546 }
 547
 548 static void tcf_chain_hold(struct tcf_chain *chain)
 549 {
 550         ASSERT_BLOCK_LOCKED(chain->block);
 551
 552         ++chain->refcnt;
 553 }
 554
 555 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 556 {
 557         ASSERT_BLOCK_LOCKED(chain->block);
 558
 559         /* In case all the references are action references, this
 560          * chain should not be shown to the user.
 561          */
 562         return chain->refcnt == chain->action_refcnt;
 563 }
 564
 565 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 566                                           u32 chain_index)
 567 {
 568         struct tcf_chain *chain;
 569
 570         ASSERT_BLOCK_LOCKED(block);
 571
 572         list_for_each_entry(chain, &block->chain_list, list) {
 573                 if (chain->index == chain_index)
 574                         return chain;
 575         }
 576         return NULL;
 577 }
 578
 579 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 580 static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block,
 581                                               u32 chain_index)
 582 {
 583         struct tcf_chain *chain;
 584
 585         list_for_each_entry_rcu(chain, &block->chain_list, list) {
 586                 if (chain->index == chain_index)
 587                         return chain;
 588         }
 589         return NULL;
 590 }
 591 #endif
 592
 593 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 594                            u32 seq, u16 flags, int event, bool unicast,
 595                            struct netlink_ext_ack *extack);
 596
 597 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 598                                          u32 chain_index, bool create,
 599                                          bool by_act)
 600 {
 601         struct tcf_chain *chain = NULL;
 602         bool is_first_reference;
 603
 604         mutex_lock(&block->lock);
 605         chain = tcf_chain_lookup(block, chain_index);
 606         if (chain) {
 607                 tcf_chain_hold(chain);
 608         } else {
 609                 if (!create)
 610                         goto errout;
 611                 chain = tcf_chain_create(block, chain_index);
 612                 if (!chain)
 613                         goto errout;
 614         }
 615
 616         if (by_act)
 617                 ++chain->action_refcnt;
 618         is_first_reference = chain->refcnt - chain->action_refcnt == 1;
 619         mutex_unlock(&block->lock);
 620
 621         /* Send notification only in case we got the first
 622          * non-action reference. Until then, the chain acts only as
 623          * a placeholder for actions pointing to it and user ought
 624          * not know about them.
 625          */
 626         if (is_first_reference && !by_act)
 627                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 628                                 RTM_NEWCHAIN, false, NULL);
 629
 630         return chain;
 631
 632 errout:
 633         mutex_unlock(&block->lock);
 634         return chain;
 635 }
 636
 637 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 638                                        bool create)
 639 {
 640         return __tcf_chain_get(block, chain_index, create, false);
 641 }
 642
 643 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 644 {
 645         return __tcf_chain_get(block, chain_index, true, true);
 646 }
 647 EXPORT_SYMBOL(tcf_chain_get_by_act);
 648
 649 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
 650                                void *tmplt_priv);
 651 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
 652                                   void *tmplt_priv, u32 chain_index,
 653                                   struct tcf_block *block, struct sk_buff *oskb,
 654                                   u32 seq, u16 flags);
 655
 656 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 657                             bool explicitly_created)
 658 {
 659         struct tcf_block *block = chain->block;
 660         const struct tcf_proto_ops *tmplt_ops;
 661         unsigned int refcnt, non_act_refcnt;
 662         bool free_block = false;
 663         void *tmplt_priv;
 664
 665         mutex_lock(&block->lock);
 666         if (explicitly_created) {
 667                 if (!chain->explicitly_created) {
 668                         mutex_unlock(&block->lock);
 669                         return;
 670                 }
 671                 chain->explicitly_created = false;
 672         }
 673
 674         if (by_act)
 675                 chain->action_refcnt--;
 676
 677         /* tc_chain_notify_delete can't be called while holding block lock.
 678          * However, when block is unlocked chain can be changed concurrently, so
 679          * save these to temporary variables.
 680          */
 681         refcnt = --chain->refcnt;
 682         non_act_refcnt = refcnt - chain->action_refcnt;
 683         tmplt_ops = chain->tmplt_ops;
 684         tmplt_priv = chain->tmplt_priv;
 685
 686         if (non_act_refcnt == chain->explicitly_created && !by_act) {
 687                 if (non_act_refcnt == 0)
 688                         tc_chain_notify_delete(tmplt_ops, tmplt_priv,
 689                                                chain->index, block, NULL, 0, 0);
 690                 /* Last reference to chain, no need to lock. */
 691                 chain->flushing = false;
 692         }
 693
 694         if (refcnt == 0)
 695                 free_block = tcf_chain_detach(chain);
 696         mutex_unlock(&block->lock);
 697
 698         if (refcnt == 0) {
 699                 tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 700                 tcf_chain_destroy(chain, free_block);
 701         }
 702 }
 703
 704 static void tcf_chain_put(struct tcf_chain *chain)
 705 {
 706         __tcf_chain_put(chain, false, false);
 707 }
 708
 709 void tcf_chain_put_by_act(struct tcf_chain *chain)
 710 {
 711         __tcf_chain_put(chain, true, false);
 712 }
 713 EXPORT_SYMBOL(tcf_chain_put_by_act);
 714
 715 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 716 {
 717         __tcf_chain_put(chain, false, true);
 718 }
 719
 720 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 721 {
 722         struct tcf_proto *tp, *tp_next;
 723
 724         mutex_lock(&chain->filter_chain_lock);
 725         tp = tcf_chain_dereference(chain->filter_chain, chain);
 726         while (tp) {
 727                 tp_next = rcu_dereference_protected(tp->next, 1);
 728                 tcf_proto_signal_destroying(chain, tp);
 729                 tp = tp_next;
 730         }
 731         tp = tcf_chain_dereference(chain->filter_chain, chain);
 732         RCU_INIT_POINTER(chain->filter_chain, NULL);
 733         tcf_chain0_head_change(chain, NULL);
 734         chain->flushing = true;
 735         mutex_unlock(&chain->filter_chain_lock);
 736
 737         while (tp) {
 738                 tp_next = rcu_dereference_protected(tp->next, 1);
 739                 tcf_proto_put(tp, rtnl_held, NULL);
 740                 tp = tp_next;
 741         }
 742 }
 743
 744 static int tcf_block_setup(struct tcf_block *block,
 745                            struct flow_block_offload *bo);
 746
 747 static void tcf_block_offload_init(struct flow_block_offload *bo,
 748                                    struct net_device *dev, struct Qdisc *sch,
 749                                    enum flow_block_command command,
 750                                    enum flow_block_binder_type binder_type,
 751                                    struct flow_block *flow_block,
 752                                    bool shared, struct netlink_ext_ack *extack)
 753 {
 754         bo->net = dev_net(dev);
 755         bo->command = command;
 756         bo->binder_type = binder_type;
 757         bo->block = flow_block;
 758         bo->block_shared = shared;
 759         bo->extack = extack;
 760         bo->sch = sch;
 761         bo->cb_list_head = &flow_block->cb_list;
 762         INIT_LIST_HEAD(&bo->cb_list);
 763 }
 764
 765 static void tcf_block_unbind(struct tcf_block *block,
 766                              struct flow_block_offload *bo);
 767
 768 static void tc_block_indr_cleanup(struct flow_block_cb *block_cb)
 769 {
 770         struct tcf_block *block = block_cb->indr.data;
 771         struct net_device *dev = block_cb->indr.dev;
 772         struct Qdisc *sch = block_cb->indr.sch;
 773         struct netlink_ext_ack extack = {};
 774         struct flow_block_offload bo = {};
 775
 776         tcf_block_offload_init(&bo, dev, sch, FLOW_BLOCK_UNBIND,
 777                                block_cb->indr.binder_type,
 778                                &block->flow_block, tcf_block_shared(block),
 779                                &extack);
 780         rtnl_lock();
 781         down_write(&block->cb_lock);
 782         list_del(&block_cb->driver_list);
 783         list_move(&block_cb->list, &bo.cb_list);
 784         tcf_block_unbind(block, &bo);
 785         up_write(&block->cb_lock);
 786         rtnl_unlock();
 787 }
 788
 789 static bool tcf_block_offload_in_use(struct tcf_block *block)
 790 {
 791         return atomic_read(&block->offloadcnt);
 792 }
 793
 794 static int tcf_block_offload_cmd(struct tcf_block *block,
 795                                  struct net_device *dev, struct Qdisc *sch,
 796                                  struct tcf_block_ext_info *ei,
 797                                  enum flow_block_command command,
 798                                  struct netlink_ext_ack *extack)
 799 {
 800         struct flow_block_offload bo = {};
 801
 802         tcf_block_offload_init(&bo, dev, sch, command, ei->binder_type,
 803                                &block->flow_block, tcf_block_shared(block),
 804                                extack);
 805
 806         if (dev->netdev_ops->ndo_setup_tc) {
 807                 int err;
 808
 809                 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 810                 if (err < 0) {
 811                         if (err != -EOPNOTSUPP)
 812                                 NL_SET_ERR_MSG(extack, "Driver ndo_setup_tc failed");
 813                         return err;
 814                 }
 815
 816                 return tcf_block_setup(block, &bo);
 817         }
 818
 819         flow_indr_dev_setup_offload(dev, sch, TC_SETUP_BLOCK, block, &bo,
 820                                     tc_block_indr_cleanup);
 821         tcf_block_setup(block, &bo);
 822
 823         return -EOPNOTSUPP;
 824 }
 825
 826 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 827                                   struct tcf_block_ext_info *ei,
 828                                   struct netlink_ext_ack *extack)
 829 {
 830         struct net_device *dev = q->dev_queue->dev;
 831         int err;
 832
 833         down_write(&block->cb_lock);
 834
 835         /* If tc offload feature is disabled and the block we try to bind
 836          * to already has some offloaded filters, forbid to bind.
 837          */
 838         if (dev->netdev_ops->ndo_setup_tc &&
 839             !tc_can_offload(dev) &&
 840             tcf_block_offload_in_use(block)) {
 841                 NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
 842                 err = -EOPNOTSUPP;
 843                 goto err_unlock;
 844         }
 845
 846         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_BIND, extack);
 847         if (err == -EOPNOTSUPP)
 848                 goto no_offload_dev_inc;
 849         if (err)
 850                 goto err_unlock;
 851
 852         up_write(&block->cb_lock);
 853         return 0;
 854
 855 no_offload_dev_inc:
 856         if (tcf_block_offload_in_use(block))
 857                 goto err_unlock;
 858
 859         err = 0;
 860         block->nooffloaddevcnt++;
 861 err_unlock:
 862         up_write(&block->cb_lock);
 863         return err;
 864 }
 865
 866 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 867                                      struct tcf_block_ext_info *ei)
 868 {
 869         struct net_device *dev = q->dev_queue->dev;
 870         int err;
 871
 872         down_write(&block->cb_lock);
 873         err = tcf_block_offload_cmd(block, dev, q, ei, FLOW_BLOCK_UNBIND, NULL);
 874         if (err == -EOPNOTSUPP)
 875                 goto no_offload_dev_dec;
 876         up_write(&block->cb_lock);
 877         return;
 878
 879 no_offload_dev_dec:
 880         WARN_ON(block->nooffloaddevcnt-- == 0);
 881         up_write(&block->cb_lock);
 882 }
 883
 884 static int
 885 tcf_chain0_head_change_cb_add(struct tcf_block *block,
 886                               struct tcf_block_ext_info *ei,
 887                               struct netlink_ext_ack *extack)
 888 {
 889         struct tcf_filter_chain_list_item *item;
 890         struct tcf_chain *chain0;
 891
 892         item = kmalloc(sizeof(*item), GFP_KERNEL);
 893         if (!item) {
 894                 NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
 895                 return -ENOMEM;
 896         }
 897         item->chain_head_change = ei->chain_head_change;
 898         item->chain_head_change_priv = ei->chain_head_change_priv;
 899
 900         mutex_lock(&block->lock);
 901         chain0 = block->chain0.chain;
 902         if (chain0)
 903                 tcf_chain_hold(chain0);
 904         else
 905                 list_add(&item->list, &block->chain0.filter_chain_list);
 906         mutex_unlock(&block->lock);
 907
 908         if (chain0) {
 909                 struct tcf_proto *tp_head;
 910
 911                 mutex_lock(&chain0->filter_chain_lock);
 912
 913                 tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
 914                 if (tp_head)
 915                         tcf_chain_head_change_item(item, tp_head);
 916
 917                 mutex_lock(&block->lock);
 918                 list_add(&item->list, &block->chain0.filter_chain_list);
 919                 mutex_unlock(&block->lock);
 920
 921                 mutex_unlock(&chain0->filter_chain_lock);
 922                 tcf_chain_put(chain0);
 923         }
 924
 925         return 0;
 926 }
 927
 928 static void
 929 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 930                               struct tcf_block_ext_info *ei)
 931 {
 932         struct tcf_filter_chain_list_item *item;
 933
 934         mutex_lock(&block->lock);
 935         list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 936                 if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 937                     (item->chain_head_change == ei->chain_head_change &&
 938                      item->chain_head_change_priv == ei->chain_head_change_priv)) {
 939                         if (block->chain0.chain)
 940                                 tcf_chain_head_change_item(item, NULL);
 941                         list_del(&item->list);
 942                         mutex_unlock(&block->lock);
 943
 944                         kfree(item);
 945                         return;
 946                 }
 947         }
 948         mutex_unlock(&block->lock);
 949         WARN_ON(1);
 950 }
 951
 952 struct tcf_net {
 953         spinlock_t idr_lock; /* Protects idr */
 954         struct idr idr;
 955 };
 956
 957 static unsigned int tcf_net_id;
 958
 959 static int tcf_block_insert(struct tcf_block *block, struct net *net,
 960                             struct netlink_ext_ack *extack)
 961 {
 962         struct tcf_net *tn = net_generic(net, tcf_net_id);
 963         int err;
 964
 965         idr_preload(GFP_KERNEL);
 966         spin_lock(&tn->idr_lock);
 967         err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
 968                             GFP_NOWAIT);
 969         spin_unlock(&tn->idr_lock);
 970         idr_preload_end();
 971
 972         return err;
 973 }
 974
 975 static void tcf_block_remove(struct tcf_block *block, struct net *net)
 976 {
 977         struct tcf_net *tn = net_generic(net, tcf_net_id);
 978
 979         spin_lock(&tn->idr_lock);
 980         idr_remove(&tn->idr, block->index);
 981         spin_unlock(&tn->idr_lock);
 982 }
 983
 984 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 985                                           u32 block_index,
 986                                           struct netlink_ext_ack *extack)
 987 {
 988         struct tcf_block *block;
 989
 990         block = kzalloc(sizeof(*block), GFP_KERNEL);
 991         if (!block) {
 992                 NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 993                 return ERR_PTR(-ENOMEM);
 994         }
 995         mutex_init(&block->lock);
 996         mutex_init(&block->proto_destroy_lock);
 997         init_rwsem(&block->cb_lock);
 998         flow_block_init(&block->flow_block);
 999         INIT_LIST_HEAD(&block->chain_list);
1000         INIT_LIST_HEAD(&block->owner_list);
1001         INIT_LIST_HEAD(&block->chain0.filter_chain_list);
1002
1003         refcount_set(&block->refcnt, 1);
1004         block->net = net;
1005         block->index = block_index;
1006         xa_init(&block->ports);
1007
1008         /* Don't store q pointer for blocks which are shared */
1009         if (!tcf_block_shared(block))
1010                 block->q = q;
1011         return block;
1012 }
1013
1014 struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
1015 {
1016         struct tcf_net *tn = net_generic(net, tcf_net_id);
1017
1018         return idr_find(&tn->idr, block_index);
1019 }
1020 EXPORT_SYMBOL(tcf_block_lookup);
1021
1022 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
1023 {
1024         struct tcf_block *block;
1025
1026         rcu_read_lock();
1027         block = tcf_block_lookup(net, block_index);
1028         if (block && !refcount_inc_not_zero(&block->refcnt))
1029                 block = NULL;
1030         rcu_read_unlock();
1031
1032         return block;
1033 }
1034
1035 static struct tcf_chain *
1036 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1037 {
1038         mutex_lock(&block->lock);
1039         if (chain)
1040                 chain = list_is_last(&chain->list, &block->chain_list) ?
1041                         NULL : list_next_entry(chain, list);
1042         else
1043                 chain = list_first_entry_or_null(&block->chain_list,
1044                                                  struct tcf_chain, list);
1045
1046         /* skip all action-only chains */
1047         while (chain && tcf_chain_held_by_acts_only(chain))
1048                 chain = list_is_last(&chain->list, &block->chain_list) ?
1049                         NULL : list_next_entry(chain, list);
1050
1051         if (chain)
1052                 tcf_chain_hold(chain);
1053         mutex_unlock(&block->lock);
1054
1055         return chain;
1056 }
1057
1058 /* Function to be used by all clients that want to iterate over all chains on
1059  * block. It properly obtains block->lock and takes reference to chain before
1060  * returning it. Users of this function must be tolerant to concurrent chain
1061  * insertion/deletion or ensure that no concurrent chain modification is
1062  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1063  * consistent dump because rtnl lock is released each time skb is filled with
1064  * data and sent to user-space.
1065  */
1066
1067 struct tcf_chain *
1068 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1069 {
1070         struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
1071
1072         if (chain)
1073                 tcf_chain_put(chain);
1074
1075         return chain_next;
1076 }
1077 EXPORT_SYMBOL(tcf_get_next_chain);
1078
1079 static struct tcf_proto *
1080 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1081 {
1082         u32 prio = 0;
1083
1084         ASSERT_RTNL();
1085         mutex_lock(&chain->filter_chain_lock);
1086
1087         if (!tp) {
1088                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1089         } else if (tcf_proto_is_deleting(tp)) {
1090                 /* 'deleting' flag is set and chain->filter_chain_lock was
1091                  * unlocked, which means next pointer could be invalid. Restart
1092                  * search.
1093                  */
1094                 prio = tp->prio + 1;
1095                 tp = tcf_chain_dereference(chain->filter_chain, chain);
1096
1097                 for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1098                         if (!tp->deleting && tp->prio >= prio)
1099                                 break;
1100         } else {
1101                 tp = tcf_chain_dereference(tp->next, chain);
1102         }
1103
1104         if (tp)
1105                 tcf_proto_get(tp);
1106
1107         mutex_unlock(&chain->filter_chain_lock);
1108
1109         return tp;
1110 }
1111
1112 /* Function to be used by all clients that want to iterate over all tp's on
1113  * chain. Users of this function must be tolerant to concurrent tp
1114  * insertion/deletion or ensure that no concurrent chain modification is
1115  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1116  * consistent dump because rtnl lock is released each time skb is filled with
1117  * data and sent to user-space.
1118  */
1119
1120 struct tcf_proto *
1121 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1122 {
1123         struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1124
1125         if (tp)
1126                 tcf_proto_put(tp, true, NULL);
1127
1128         return tp_next;
1129 }
1130 EXPORT_SYMBOL(tcf_get_next_proto);
1131
1132 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1133 {
1134         struct tcf_chain *chain;
1135
1136         /* Last reference to block. At this point chains cannot be added or
1137          * removed concurrently.
1138          */
1139         for (chain = tcf_get_next_chain(block, NULL);
1140              chain;
1141              chain = tcf_get_next_chain(block, chain)) {
1142                 tcf_chain_put_explicitly_created(chain);
1143                 tcf_chain_flush(chain, rtnl_held);
1144         }
1145 }
1146
1147 /* Lookup Qdisc and increments its reference counter.
1148  * Set parent, if necessary.
1149  */
1150
1151 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1152                             u32 *parent, int ifindex, bool rtnl_held,
1153                             struct netlink_ext_ack *extack)
1154 {
1155         const struct Qdisc_class_ops *cops;
1156         struct net_device *dev;
1157         int err = 0;
1158
1159         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1160                 return 0;
1161
1162         rcu_read_lock();
1163
1164         /* Find link */
1165         dev = dev_get_by_index_rcu(net, ifindex);
1166         if (!dev) {
1167                 rcu_read_unlock();
1168                 return -ENODEV;
1169         }
1170
1171         /* Find qdisc */
1172         if (!*parent) {
1173                 *q = rcu_dereference(dev->qdisc);
1174                 *parent = (*q)->handle;
1175         } else {
1176                 *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1177                 if (!*q) {
1178                         NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1179                         err = -EINVAL;
1180                         goto errout_rcu;
1181                 }
1182         }
1183
1184         *q = qdisc_refcount_inc_nz(*q);
1185         if (!*q) {
1186                 NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1187                 err = -EINVAL;
1188                 goto errout_rcu;
1189         }
1190
1191         /* Is it classful? */
1192         cops = (*q)->ops->cl_ops;
1193         if (!cops) {
1194                 NL_SET_ERR_MSG(extack, "Qdisc not classful");
1195                 err = -EINVAL;
1196                 goto errout_qdisc;
1197         }
1198
1199         if (!cops->tcf_block) {
1200                 NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1201                 err = -EOPNOTSUPP;
1202                 goto errout_qdisc;
1203         }
1204
1205 errout_rcu:
1206         /* At this point we know that qdisc is not noop_qdisc,
1207          * which means that qdisc holds a reference to net_device
1208          * and we hold a reference to qdisc, so it is safe to release
1209          * rcu read lock.
1210          */
1211         rcu_read_unlock();
1212         return err;
1213
1214 errout_qdisc:
1215         rcu_read_unlock();
1216
1217         if (rtnl_held)
1218                 qdisc_put(*q);
1219         else
1220                 qdisc_put_unlocked(*q);
1221         *q = NULL;
1222
1223         return err;
1224 }
1225
1226 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1227                                int ifindex, struct netlink_ext_ack *extack)
1228 {
1229         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1230                 return 0;
1231
1232         /* Do we search for filter, attached to class? */
1233         if (TC_H_MIN(parent)) {
1234                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1235
1236                 *cl = cops->find(q, parent);
1237                 if (*cl == 0) {
1238                         NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1239                         return -ENOENT;
1240                 }
1241         }
1242
1243         return 0;
1244 }
1245
1246 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1247                                           unsigned long cl, int ifindex,
1248                                           u32 block_index,
1249                                           struct netlink_ext_ack *extack)
1250 {
1251         struct tcf_block *block;
1252
1253         if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1254                 block = tcf_block_refcnt_get(net, block_index);
1255                 if (!block) {
1256                         NL_SET_ERR_MSG(extack, "Block of given index was not found");
1257                         return ERR_PTR(-EINVAL);
1258                 }
1259         } else {
1260                 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1261
1262                 block = cops->tcf_block(q, cl, extack);
1263                 if (!block)
1264                         return ERR_PTR(-EINVAL);
1265
1266                 if (tcf_block_shared(block)) {
1267                         NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1268                         return ERR_PTR(-EOPNOTSUPP);
1269                 }
1270
1271                 /* Always take reference to block in order to support execution
1272                  * of rules update path of cls API without rtnl lock. Caller
1273                  * must release block when it is finished using it. 'if' block
1274                  * of this conditional obtain reference to block by calling
1275                  * tcf_block_refcnt_get().
1276                  */
1277                 refcount_inc(&block->refcnt);
1278         }
1279
1280         return block;
1281 }
1282
1283 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1284                             struct tcf_block_ext_info *ei, bool rtnl_held)
1285 {
1286         if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1287                 /* Flushing/putting all chains will cause the block to be
1288                  * deallocated when last chain is freed. However, if chain_list
1289                  * is empty, block has to be manually deallocated. After block
1290                  * reference counter reached 0, it is no longer possible to
1291                  * increment it or add new chains to block.
1292                  */
1293                 bool free_block = list_empty(&block->chain_list);
1294
1295                 mutex_unlock(&block->lock);
1296                 if (tcf_block_shared(block))
1297                         tcf_block_remove(block, block->net);
1298
1299                 if (q)
1300                         tcf_block_offload_unbind(block, q, ei);
1301
1302                 if (free_block)
1303                         tcf_block_destroy(block);
1304                 else
1305                         tcf_block_flush_all_chains(block, rtnl_held);
1306         } else if (q) {
1307                 tcf_block_offload_unbind(block, q, ei);
1308         }
1309 }
1310
1311 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1312 {
1313         __tcf_block_put(block, NULL, NULL, rtnl_held);
1314 }
1315
1316 /* Find tcf block.
1317  * Set q, parent, cl when appropriate.
1318  */
1319
1320 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1321                                         u32 *parent, unsigned long *cl,
1322                                         int ifindex, u32 block_index,
1323                                         struct netlink_ext_ack *extack)
1324 {
1325         struct tcf_block *block;
1326         int err = 0;
1327
1328         ASSERT_RTNL();
1329
1330         err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1331         if (err)
1332                 goto errout;
1333
1334         err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1335         if (err)
1336                 goto errout_qdisc;
1337
1338         block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1339         if (IS_ERR(block)) {
1340                 err = PTR_ERR(block);
1341                 goto errout_qdisc;
1342         }
1343
1344         return block;
1345
1346 errout_qdisc:
1347         if (*q)
1348                 qdisc_put(*q);
1349 errout:
1350         *q = NULL;
1351         return ERR_PTR(err);
1352 }
1353
1354 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1355                               bool rtnl_held)
1356 {
1357         if (!IS_ERR_OR_NULL(block))
1358                 tcf_block_refcnt_put(block, rtnl_held);
1359
1360         if (q) {
1361                 if (rtnl_held)
1362                         qdisc_put(q);
1363                 else
1364                         qdisc_put_unlocked(q);
1365         }
1366 }
1367
1368 struct tcf_block_owner_item {
1369         struct list_head list;
1370         struct Qdisc *q;
1371         enum flow_block_binder_type binder_type;
1372 };
1373
1374 static void
1375 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1376                                struct Qdisc *q,
1377                                enum flow_block_binder_type binder_type)
1378 {
1379         if (block->keep_dst &&
1380             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1381             binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1382                 netif_keep_dst(qdisc_dev(q));
1383 }
1384
1385 void tcf_block_netif_keep_dst(struct tcf_block *block)
1386 {
1387         struct tcf_block_owner_item *item;
1388
1389         block->keep_dst = true;
1390         list_for_each_entry(item, &block->owner_list, list)
1391                 tcf_block_owner_netif_keep_dst(block, item->q,
1392                                                item->binder_type);
1393 }
1394 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1395
1396 static int tcf_block_owner_add(struct tcf_block *block,
1397                                struct Qdisc *q,
1398                                enum flow_block_binder_type binder_type)
1399 {
1400         struct tcf_block_owner_item *item;
1401
1402         item = kmalloc(sizeof(*item), GFP_KERNEL);
1403         if (!item)
1404                 return -ENOMEM;
1405         item->q = q;
1406         item->binder_type = binder_type;
1407         list_add(&item->list, &block->owner_list);
1408         return 0;
1409 }
1410
1411 static void tcf_block_owner_del(struct tcf_block *block,
1412                                 struct Qdisc *q,
1413                                 enum flow_block_binder_type binder_type)
1414 {
1415         struct tcf_block_owner_item *item;
1416
1417         list_for_each_entry(item, &block->owner_list, list) {
1418                 if (item->q == q && item->binder_type == binder_type) {
1419                         list_del(&item->list);
1420                         kfree(item);
1421                         return;
1422                 }
1423         }
1424         WARN_ON(1);
1425 }
1426
1427 static bool tcf_block_tracks_dev(struct tcf_block *block,
1428                                  struct tcf_block_ext_info *ei)
1429 {
1430         return tcf_block_shared(block) &&
1431                (ei->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS ||
1432                 ei->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS);
1433 }
1434
1435 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1436                       struct tcf_block_ext_info *ei,
1437                       struct netlink_ext_ack *extack)
1438 {
1439         struct net_device *dev = qdisc_dev(q);
1440         struct net *net = qdisc_net(q);
1441         struct tcf_block *block = NULL;
1442         int err;
1443
1444         if (ei->block_index)
1445                 /* block_index not 0 means the shared block is requested */
1446                 block = tcf_block_refcnt_get(net, ei->block_index);
1447
1448         if (!block) {
1449                 block = tcf_block_create(net, q, ei->block_index, extack);
1450                 if (IS_ERR(block))
1451                         return PTR_ERR(block);
1452                 if (tcf_block_shared(block)) {
1453                         err = tcf_block_insert(block, net, extack);
1454                         if (err)
1455                                 goto err_block_insert;
1456                 }
1457         }
1458
1459         err = tcf_block_owner_add(block, q, ei->binder_type);
1460         if (err)
1461                 goto err_block_owner_add;
1462
1463         tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1464
1465         err = tcf_chain0_head_change_cb_add(block, ei, extack);
1466         if (err)
1467                 goto err_chain0_head_change_cb_add;
1468
1469         err = tcf_block_offload_bind(block, q, ei, extack);
1470         if (err)
1471                 goto err_block_offload_bind;
1472
1473         if (tcf_block_tracks_dev(block, ei)) {
1474                 err = xa_insert(&block->ports, dev->ifindex, dev, GFP_KERNEL);
1475                 if (err) {
1476                         NL_SET_ERR_MSG(extack, "block dev insert failed");
1477                         goto err_dev_insert;
1478                 }
1479         }
1480
1481         *p_block = block;
1482         return 0;
1483
1484 err_dev_insert:
1485 err_block_offload_bind:
1486         tcf_chain0_head_change_cb_del(block, ei);
1487 err_chain0_head_change_cb_add:
1488         tcf_block_owner_del(block, q, ei->binder_type);
1489 err_block_owner_add:
1490 err_block_insert:
1491         tcf_block_refcnt_put(block, true);
1492         return err;
1493 }
1494 EXPORT_SYMBOL(tcf_block_get_ext);
1495
1496 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1497 {
1498         struct tcf_proto __rcu **p_filter_chain = priv;
1499
1500         rcu_assign_pointer(*p_filter_chain, tp_head);
1501 }
1502
1503 int tcf_block_get(struct tcf_block **p_block,
1504                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1505                   struct netlink_ext_ack *extack)
1506 {
1507         struct tcf_block_ext_info ei = {
1508                 .chain_head_change = tcf_chain_head_change_dflt,
1509                 .chain_head_change_priv = p_filter_chain,
1510         };
1511
1512         WARN_ON(!p_filter_chain);
1513         return tcf_block_get_ext(p_block, q, &ei, extack);
1514 }
1515 EXPORT_SYMBOL(tcf_block_get);
1516
1517 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1518  * actions should be all removed after flushing.
1519  */
1520 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1521                        struct tcf_block_ext_info *ei)
1522 {
1523         struct net_device *dev = qdisc_dev(q);
1524
1525         if (!block)
1526                 return;
1527         if (tcf_block_tracks_dev(block, ei))
1528                 xa_erase(&block->ports, dev->ifindex);
1529         tcf_chain0_head_change_cb_del(block, ei);
1530         tcf_block_owner_del(block, q, ei->binder_type);
1531
1532         __tcf_block_put(block, q, ei, true);
1533 }
1534 EXPORT_SYMBOL(tcf_block_put_ext);
1535
1536 void tcf_block_put(struct tcf_block *block)
1537 {
1538         struct tcf_block_ext_info ei = {0, };
1539
1540         if (!block)
1541                 return;
1542         tcf_block_put_ext(block, block->q, &ei);
1543 }
1544
1545 EXPORT_SYMBOL(tcf_block_put);
1546
1547 static int
1548 tcf_block_playback_offloads(struct tcf_block *block, flow_setup_cb_t *cb,
1549                             void *cb_priv, bool add, bool offload_in_use,
1550                             struct netlink_ext_ack *extack)
1551 {
1552         struct tcf_chain *chain, *chain_prev;
1553         struct tcf_proto *tp, *tp_prev;
1554         int err;
1555
1556         lockdep_assert_held(&block->cb_lock);
1557
1558         for (chain = __tcf_get_next_chain(block, NULL);
1559              chain;
1560              chain_prev = chain,
1561                      chain = __tcf_get_next_chain(block, chain),
1562                      tcf_chain_put(chain_prev)) {
1563                 if (chain->tmplt_ops && add)
1564                         chain->tmplt_ops->tmplt_reoffload(chain, true, cb,
1565                                                           cb_priv);
1566                 for (tp = __tcf_get_next_proto(chain, NULL); tp;
1567                      tp_prev = tp,
1568                              tp = __tcf_get_next_proto(chain, tp),
1569                              tcf_proto_put(tp_prev, true, NULL)) {
1570                         if (tp->ops->reoffload) {
1571                                 err = tp->ops->reoffload(tp, add, cb, cb_priv,
1572                                                          extack);
1573                                 if (err && add)
1574                                         goto err_playback_remove;
1575                         } else if (add && offload_in_use) {
1576                                 err = -EOPNOTSUPP;
1577                                 NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1578                                 goto err_playback_remove;
1579                         }
1580                 }
1581                 if (chain->tmplt_ops && !add)
1582                         chain->tmplt_ops->tmplt_reoffload(chain, false, cb,
1583                                                           cb_priv);
1584         }
1585
1586         return 0;
1587
1588 err_playback_remove:
1589         tcf_proto_put(tp, true, NULL);
1590         tcf_chain_put(chain);
1591         tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1592                                     extack);
1593         return err;
1594 }
1595
1596 static int tcf_block_bind(struct tcf_block *block,
1597                           struct flow_block_offload *bo)
1598 {
1599         struct flow_block_cb *block_cb, *next;
1600         int err, i = 0;
1601
1602         lockdep_assert_held(&block->cb_lock);
1603
1604         list_for_each_entry(block_cb, &bo->cb_list, list) {
1605                 err = tcf_block_playback_offloads(block, block_cb->cb,
1606                                                   block_cb->cb_priv, true,
1607                                                   tcf_block_offload_in_use(block),
1608                                                   bo->extack);
1609                 if (err)
1610                         goto err_unroll;
1611                 if (!bo->unlocked_driver_cb)
1612                         block->lockeddevcnt++;
1613
1614                 i++;
1615         }
1616         list_splice(&bo->cb_list, &block->flow_block.cb_list);
1617
1618         return 0;
1619
1620 err_unroll:
1621         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1622                 list_del(&block_cb->driver_list);
1623                 if (i-- > 0) {
1624                         list_del(&block_cb->list);
1625                         tcf_block_playback_offloads(block, block_cb->cb,
1626                                                     block_cb->cb_priv, false,
1627                                                     tcf_block_offload_in_use(block),
1628                                                     NULL);
1629                         if (!bo->unlocked_driver_cb)
1630                                 block->lockeddevcnt--;
1631                 }
1632                 flow_block_cb_free(block_cb);
1633         }
1634
1635         return err;
1636 }
1637
1638 static void tcf_block_unbind(struct tcf_block *block,
1639                              struct flow_block_offload *bo)
1640 {
1641         struct flow_block_cb *block_cb, *next;
1642
1643         lockdep_assert_held(&block->cb_lock);
1644
1645         list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
1646                 tcf_block_playback_offloads(block, block_cb->cb,
1647                                             block_cb->cb_priv, false,
1648                                             tcf_block_offload_in_use(block),
1649                                             NULL);
1650                 list_del(&block_cb->list);
1651                 flow_block_cb_free(block_cb);
1652                 if (!bo->unlocked_driver_cb)
1653                         block->lockeddevcnt--;
1654         }
1655 }
1656
1657 static int tcf_block_setup(struct tcf_block *block,
1658                            struct flow_block_offload *bo)
1659 {
1660         int err;
1661
1662         switch (bo->command) {
1663         case FLOW_BLOCK_BIND:
1664                 err = tcf_block_bind(block, bo);
1665                 break;
1666         case FLOW_BLOCK_UNBIND:
1667                 err = 0;
1668                 tcf_block_unbind(block, bo);
1669                 break;
1670         default:
1671                 WARN_ON_ONCE(1);
1672                 err = -EOPNOTSUPP;
1673         }
1674
1675         return err;
1676 }
1677
1678 /* Main classifier routine: scans classifier chain attached
1679  * to this qdisc, (optionally) tests for protocol and asks
1680  * specific classifiers.
1681  */
1682 static inline int __tcf_classify(struct sk_buff *skb,
1683                                  const struct tcf_proto *tp,
1684                                  const struct tcf_proto *orig_tp,
1685                                  struct tcf_result *res,
1686                                  bool compat_mode,
1687                                  struct tcf_exts_miss_cookie_node *n,
1688                                  int act_index,
1689                                  u32 *last_executed_chain)
1690 {
1691 #ifdef CONFIG_NET_CLS_ACT
1692         const int max_reclassify_loop = 16;
1693         const struct tcf_proto *first_tp;
1694         int limit = 0;
1695
1696 reclassify:
1697 #endif
1698         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1699                 __be16 protocol = skb_protocol(skb, false);
1700                 int err = 0;
1701
1702                 if (n) {
1703                         struct tcf_exts *exts;
1704
1705                         if (n->tp_prio != tp->prio)
1706                                 continue;
1707
1708                         /* We re-lookup the tp and chain based on index instead
1709                          * of having hard refs and locks to them, so do a sanity
1710                          * check if any of tp,chain,exts was replaced by the
1711                          * time we got here with a cookie from hardware.
1712                          */
1713                         if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
1714                                      !tp->ops->get_exts)) {
1715                                 tcf_set_drop_reason(skb,
1716                                                     SKB_DROP_REASON_TC_COOKIE_ERROR);
1717                                 return TC_ACT_SHOT;
1718                         }
1719
1720                         exts = tp->ops->get_exts(tp, n->handle);
1721                         if (unlikely(!exts || n->exts != exts)) {
1722                                 tcf_set_drop_reason(skb,
1723                                                     SKB_DROP_REASON_TC_COOKIE_ERROR);
1724                                 return TC_ACT_SHOT;
1725                         }
1726
1727                         n = NULL;
1728                         err = tcf_exts_exec_ex(skb, exts, act_index, res);
1729                 } else {
1730                         if (tp->protocol != protocol &&
1731                             tp->protocol != htons(ETH_P_ALL))
1732                                 continue;
1733
1734                         err = tc_classify(skb, tp, res);
1735                 }
1736 #ifdef CONFIG_NET_CLS_ACT
1737                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1738                         first_tp = orig_tp;
1739                         *last_executed_chain = first_tp->chain->index;
1740                         goto reset;
1741                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1742                         first_tp = res->goto_tp;
1743                         *last_executed_chain = err & TC_ACT_EXT_VAL_MASK;
1744                         goto reset;
1745                 }
1746 #endif
1747                 if (err >= 0)
1748                         return err;
1749         }
1750
1751         if (unlikely(n)) {
1752                 tcf_set_drop_reason(skb,
1753                                     SKB_DROP_REASON_TC_COOKIE_ERROR);
1754                 return TC_ACT_SHOT;
1755         }
1756
1757         return TC_ACT_UNSPEC; /* signal: continue lookup */
1758 #ifdef CONFIG_NET_CLS_ACT
1759 reset:
1760         if (unlikely(limit++ >= max_reclassify_loop)) {
1761                 net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1762                                        tp->chain->block->index,
1763                                        tp->prio & 0xffff,
1764                                        ntohs(tp->protocol));
1765                 tcf_set_drop_reason(skb,
1766                                     SKB_DROP_REASON_TC_RECLASSIFY_LOOP);
1767                 return TC_ACT_SHOT;
1768         }
1769
1770         tp = first_tp;
1771         goto reclassify;
1772 #endif
1773 }
1774
1775 int tcf_classify(struct sk_buff *skb,
1776                  const struct tcf_block *block,
1777                  const struct tcf_proto *tp,
1778                  struct tcf_result *res, bool compat_mode)
1779 {
1780 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1781         u32 last_executed_chain = 0;
1782
1783         return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
1784                               &last_executed_chain);
1785 #else
1786         u32 last_executed_chain = tp ? tp->chain->index : 0;
1787         struct tcf_exts_miss_cookie_node *n = NULL;
1788         const struct tcf_proto *orig_tp = tp;
1789         struct tc_skb_ext *ext;
1790         int act_index = 0;
1791         int ret;
1792
1793         if (block) {
1794                 ext = skb_ext_find(skb, TC_SKB_EXT);
1795
1796                 if (ext && (ext->chain || ext->act_miss)) {
1797                         struct tcf_chain *fchain;
1798                         u32 chain;
1799
1800                         if (ext->act_miss) {
1801                                 n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
1802                                                                 &act_index);
1803                                 if (!n) {
1804                                         tcf_set_drop_reason(skb,
1805                                                             SKB_DROP_REASON_TC_COOKIE_ERROR);
1806                                         return TC_ACT_SHOT;
1807                                 }
1808
1809                                 chain = n->chain_index;
1810                         } else {
1811                                 chain = ext->chain;
1812                         }
1813
1814                         fchain = tcf_chain_lookup_rcu(block, chain);
1815                         if (!fchain) {
1816                                 tcf_set_drop_reason(skb,
1817                                                     SKB_DROP_REASON_TC_CHAIN_NOTFOUND);
1818
1819                                 return TC_ACT_SHOT;
1820                         }
1821
1822                         /* Consume, so cloned/redirect skbs won't inherit ext */
1823                         skb_ext_del(skb, TC_SKB_EXT);
1824
1825                         tp = rcu_dereference_bh(fchain->filter_chain);
1826                         last_executed_chain = fchain->index;
1827                 }
1828         }
1829
1830         ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, n, act_index,
1831                              &last_executed_chain);
1832
1833         if (tc_skb_ext_tc_enabled()) {
1834                 /* If we missed on some chain */
1835                 if (ret == TC_ACT_UNSPEC && last_executed_chain) {
1836                         struct tc_skb_cb *cb = tc_skb_cb(skb);
1837
1838                         ext = tc_skb_ext_alloc(skb);
1839                         if (WARN_ON_ONCE(!ext)) {
1840                                 tcf_set_drop_reason(skb, SKB_DROP_REASON_NOMEM);
1841                                 return TC_ACT_SHOT;
1842                         }
1843                         ext->chain = last_executed_chain;
1844                         ext->mru = cb->mru;
1845                         ext->post_ct = cb->post_ct;
1846                         ext->post_ct_snat = cb->post_ct_snat;
1847                         ext->post_ct_dnat = cb->post_ct_dnat;
1848                         ext->zone = cb->zone;
1849                 }
1850         }
1851
1852         return ret;
1853 #endif
1854 }
1855 EXPORT_SYMBOL(tcf_classify);
1856
1857 struct tcf_chain_info {
1858         struct tcf_proto __rcu **pprev;
1859         struct tcf_proto __rcu *next;
1860 };
1861
1862 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1863                                            struct tcf_chain_info *chain_info)
1864 {
1865         return tcf_chain_dereference(*chain_info->pprev, chain);
1866 }
1867
1868 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1869                                struct tcf_chain_info *chain_info,
1870                                struct tcf_proto *tp)
1871 {
1872         if (chain->flushing)
1873                 return -EAGAIN;
1874
1875         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1876         if (*chain_info->pprev == chain->filter_chain)
1877                 tcf_chain0_head_change(chain, tp);
1878         tcf_proto_get(tp);
1879         rcu_assign_pointer(*chain_info->pprev, tp);
1880
1881         return 0;
1882 }
1883
1884 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1885                                 struct tcf_chain_info *chain_info,
1886                                 struct tcf_proto *tp)
1887 {
1888         struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1889
1890         tcf_proto_mark_delete(tp);
1891         if (tp == chain->filter_chain)
1892                 tcf_chain0_head_change(chain, next);
1893         RCU_INIT_POINTER(*chain_info->pprev, next);
1894 }
1895
1896 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1897                                            struct tcf_chain_info *chain_info,
1898                                            u32 protocol, u32 prio,
1899                                            bool prio_allocate);
1900
1901 /* Try to insert new proto.
1902  * If proto with specified priority already exists, free new proto
1903  * and return existing one.
1904  */
1905
1906 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1907                                                     struct tcf_proto *tp_new,
1908                                                     u32 protocol, u32 prio,
1909                                                     bool rtnl_held)
1910 {
1911         struct tcf_chain_info chain_info;
1912         struct tcf_proto *tp;
1913         int err = 0;
1914
1915         mutex_lock(&chain->filter_chain_lock);
1916
1917         if (tcf_proto_exists_destroying(chain, tp_new)) {
1918                 mutex_unlock(&chain->filter_chain_lock);
1919                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1920                 return ERR_PTR(-EAGAIN);
1921         }
1922
1923         tp = tcf_chain_tp_find(chain, &chain_info,
1924                                protocol, prio, false);
1925         if (!tp)
1926                 err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1927         mutex_unlock(&chain->filter_chain_lock);
1928
1929         if (tp) {
1930                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1931                 tp_new = tp;
1932         } else if (err) {
1933                 tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
1934                 tp_new = ERR_PTR(err);
1935         }
1936
1937         return tp_new;
1938 }
1939
1940 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1941                                       struct tcf_proto *tp, bool rtnl_held,
1942                                       struct netlink_ext_ack *extack)
1943 {
1944         struct tcf_chain_info chain_info;
1945         struct tcf_proto *tp_iter;
1946         struct tcf_proto **pprev;
1947         struct tcf_proto *next;
1948
1949         mutex_lock(&chain->filter_chain_lock);
1950
1951         /* Atomically find and remove tp from chain. */
1952         for (pprev = &chain->filter_chain;
1953              (tp_iter = tcf_chain_dereference(*pprev, chain));
1954              pprev = &tp_iter->next) {
1955                 if (tp_iter == tp) {
1956                         chain_info.pprev = pprev;
1957                         chain_info.next = tp_iter->next;
1958                         WARN_ON(tp_iter->deleting);
1959                         break;
1960                 }
1961         }
1962         /* Verify that tp still exists and no new filters were inserted
1963          * concurrently.
1964          * Mark tp for deletion if it is empty.
1965          */
1966         if (!tp_iter || !tcf_proto_check_delete(tp)) {
1967                 mutex_unlock(&chain->filter_chain_lock);
1968                 return;
1969         }
1970
1971         tcf_proto_signal_destroying(chain, tp);
1972         next = tcf_chain_dereference(chain_info.next, chain);
1973         if (tp == chain->filter_chain)
1974                 tcf_chain0_head_change(chain, next);
1975         RCU_INIT_POINTER(*chain_info.pprev, next);
1976         mutex_unlock(&chain->filter_chain_lock);
1977
1978         tcf_proto_put(tp, rtnl_held, extack);
1979 }
1980
1981 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1982                                            struct tcf_chain_info *chain_info,
1983                                            u32 protocol, u32 prio,
1984                                            bool prio_allocate)
1985 {
1986         struct tcf_proto **pprev;
1987         struct tcf_proto *tp;
1988
1989         /* Check the chain for existence of proto-tcf with this priority */
1990         for (pprev = &chain->filter_chain;
1991              (tp = tcf_chain_dereference(*pprev, chain));
1992              pprev = &tp->next) {
1993                 if (tp->prio >= prio) {
1994                         if (tp->prio == prio) {
1995                                 if (prio_allocate ||
1996                                     (tp->protocol != protocol && protocol))
1997                                         return ERR_PTR(-EINVAL);
1998                         } else {
1999                                 tp = NULL;
2000                         }
2001                         break;
2002                 }
2003         }
2004         chain_info->pprev = pprev;
2005         if (tp) {
2006                 chain_info->next = tp->next;
2007                 tcf_proto_get(tp);
2008         } else {
2009                 chain_info->next = NULL;
2010         }
2011         return tp;
2012 }
2013
2014 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
2015                          struct tcf_proto *tp, struct tcf_block *block,
2016                          struct Qdisc *q, u32 parent, void *fh,
2017                          u32 portid, u32 seq, u16 flags, int event,
2018                          bool terse_dump, bool rtnl_held,
2019                          struct netlink_ext_ack *extack)
2020 {
2021         struct tcmsg *tcm;
2022         struct nlmsghdr  *nlh;
2023         unsigned char *b = skb_tail_pointer(skb);
2024
2025         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2026         if (!nlh)
2027                 goto out_nlmsg_trim;
2028         tcm = nlmsg_data(nlh);
2029         tcm->tcm_family = AF_UNSPEC;
2030         tcm->tcm__pad1 = 0;
2031         tcm->tcm__pad2 = 0;
2032         if (q) {
2033                 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
2034                 tcm->tcm_parent = parent;
2035         } else {
2036                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2037                 tcm->tcm_block_index = block->index;
2038         }
2039         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
2040         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
2041                 goto nla_put_failure;
2042         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
2043                 goto nla_put_failure;
2044         if (!fh) {
2045                 tcm->tcm_handle = 0;
2046         } else if (terse_dump) {
2047                 if (tp->ops->terse_dump) {
2048                         if (tp->ops->terse_dump(net, tp, fh, skb, tcm,
2049                                                 rtnl_held) < 0)
2050                                 goto nla_put_failure;
2051                 } else {
2052                         goto cls_op_not_supp;
2053                 }
2054         } else {
2055                 if (tp->ops->dump &&
2056                     tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
2057                         goto nla_put_failure;
2058         }
2059
2060         if (extack && extack->_msg &&
2061             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2062                 goto nla_put_failure;
2063
2064         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2065
2066         return skb->len;
2067
2068 out_nlmsg_trim:
2069 nla_put_failure:
2070 cls_op_not_supp:
2071         nlmsg_trim(skb, b);
2072         return -1;
2073 }
2074
2075 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
2076                           struct nlmsghdr *n, struct tcf_proto *tp,
2077                           struct tcf_block *block, struct Qdisc *q,
2078                           u32 parent, void *fh, int event, bool unicast,
2079                           bool rtnl_held, struct netlink_ext_ack *extack)
2080 {
2081         struct sk_buff *skb;
2082         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2083         int err = 0;
2084
2085         if (!unicast && !rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
2086                 return 0;
2087
2088         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2089         if (!skb)
2090                 return -ENOBUFS;
2091
2092         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2093                           n->nlmsg_seq, n->nlmsg_flags, event,
2094                           false, rtnl_held, extack) <= 0) {
2095                 kfree_skb(skb);
2096                 return -EINVAL;
2097         }
2098
2099         if (unicast)
2100                 err = rtnl_unicast(skb, net, portid);
2101         else
2102                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2103                                      n->nlmsg_flags & NLM_F_ECHO);
2104         return err;
2105 }
2106
2107 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
2108                               struct nlmsghdr *n, struct tcf_proto *tp,
2109                               struct tcf_block *block, struct Qdisc *q,
2110                               u32 parent, void *fh, bool *last, bool rtnl_held,
2111                               struct netlink_ext_ack *extack)
2112 {
2113         struct sk_buff *skb;
2114         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2115         int err;
2116
2117         if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
2118                 return tp->ops->delete(tp, fh, last, rtnl_held, extack);
2119
2120         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2121         if (!skb)
2122                 return -ENOBUFS;
2123
2124         if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
2125                           n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
2126                           false, rtnl_held, extack) <= 0) {
2127                 NL_SET_ERR_MSG(extack, "Failed to build del event notification");
2128                 kfree_skb(skb);
2129                 return -EINVAL;
2130         }
2131
2132         err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
2133         if (err) {
2134                 kfree_skb(skb);
2135                 return err;
2136         }
2137
2138         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2139                              n->nlmsg_flags & NLM_F_ECHO);
2140         if (err < 0)
2141                 NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
2142
2143         return err;
2144 }
2145
2146 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
2147                                  struct tcf_block *block, struct Qdisc *q,
2148                                  u32 parent, struct nlmsghdr *n,
2149                                  struct tcf_chain *chain, int event,
2150                                  struct netlink_ext_ack *extack)
2151 {
2152         struct tcf_proto *tp;
2153
2154         for (tp = tcf_get_next_proto(chain, NULL);
2155              tp; tp = tcf_get_next_proto(chain, tp))
2156                 tfilter_notify(net, oskb, n, tp, block, q, parent, NULL,
2157                                event, false, true, extack);
2158 }
2159
2160 static void tfilter_put(struct tcf_proto *tp, void *fh)
2161 {
2162         if (tp->ops->put && fh)
2163                 tp->ops->put(tp, fh);
2164 }
2165
2166 static bool is_qdisc_ingress(__u32 classid)
2167 {
2168         return (TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_INGRESS));
2169 }
2170
2171 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2172                           struct netlink_ext_ack *extack)
2173 {
2174         struct net *net = sock_net(skb->sk);
2175         struct nlattr *tca[TCA_MAX + 1];
2176         char name[IFNAMSIZ];
2177         struct tcmsg *t;
2178         u32 protocol;
2179         u32 prio;
2180         bool prio_allocate;
2181         u32 parent;
2182         u32 chain_index;
2183         struct Qdisc *q;
2184         struct tcf_chain_info chain_info;
2185         struct tcf_chain *chain;
2186         struct tcf_block *block;
2187         struct tcf_proto *tp;
2188         unsigned long cl;
2189         void *fh;
2190         int err;
2191         int tp_created;
2192         bool rtnl_held = false;
2193         u32 flags;
2194
2195 replay:
2196         tp_created = 0;
2197
2198         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2199                                      rtm_tca_policy, extack);
2200         if (err < 0)
2201                 return err;
2202
2203         t = nlmsg_data(n);
2204         protocol = TC_H_MIN(t->tcm_info);
2205         prio = TC_H_MAJ(t->tcm_info);
2206         prio_allocate = false;
2207         parent = t->tcm_parent;
2208         tp = NULL;
2209         cl = 0;
2210         block = NULL;
2211         q = NULL;
2212         chain = NULL;
2213         flags = 0;
2214
2215         if (prio == 0) {
2216                 /* If no priority is provided by the user,
2217                  * we allocate one.
2218                  */
2219                 if (n->nlmsg_flags & NLM_F_CREATE) {
2220                         prio = TC_H_MAKE(0x80000000U, 0U);
2221                         prio_allocate = true;
2222                 } else {
2223                         NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2224                         return -ENOENT;
2225                 }
2226         }
2227
2228         /* Find head of filter chain. */
2229
2230         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2231         if (err)
2232                 return err;
2233
2234         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2235                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2236                 err = -EINVAL;
2237                 goto errout;
2238         }
2239
2240         /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2241          * block is shared (no qdisc found), qdisc is not unlocked, classifier
2242          * type is not specified, classifier is not unlocked.
2243          */
2244         if (rtnl_held ||
2245             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2246             !tcf_proto_is_unlocked(name)) {
2247                 rtnl_held = true;
2248                 rtnl_lock();
2249         }
2250
2251         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2252         if (err)
2253                 goto errout;
2254
2255         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2256                                  extack);
2257         if (IS_ERR(block)) {
2258                 err = PTR_ERR(block);
2259                 goto errout;
2260         }
2261         block->classid = parent;
2262
2263         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2264         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2265                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2266                 err = -EINVAL;
2267                 goto errout;
2268         }
2269         chain = tcf_chain_get(block, chain_index, true);
2270         if (!chain) {
2271                 NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2272                 err = -ENOMEM;
2273                 goto errout;
2274         }
2275
2276         mutex_lock(&chain->filter_chain_lock);
2277         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2278                                prio, prio_allocate);
2279         if (IS_ERR(tp)) {
2280                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2281                 err = PTR_ERR(tp);
2282                 goto errout_locked;
2283         }
2284
2285         if (tp == NULL) {
2286                 struct tcf_proto *tp_new = NULL;
2287
2288                 if (chain->flushing) {
2289                         err = -EAGAIN;
2290                         goto errout_locked;
2291                 }
2292
2293                 /* Proto-tcf does not exist, create new one */
2294
2295                 if (tca[TCA_KIND] == NULL || !protocol) {
2296                         NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2297                         err = -EINVAL;
2298                         goto errout_locked;
2299                 }
2300
2301                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2302                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2303                         err = -ENOENT;
2304                         goto errout_locked;
2305                 }
2306
2307                 if (prio_allocate)
2308                         prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2309                                                                &chain_info));
2310
2311                 mutex_unlock(&chain->filter_chain_lock);
2312                 tp_new = tcf_proto_create(name, protocol, prio, chain,
2313                                           rtnl_held, extack);
2314                 if (IS_ERR(tp_new)) {
2315                         err = PTR_ERR(tp_new);
2316                         goto errout_tp;
2317                 }
2318
2319                 tp_created = 1;
2320                 tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2321                                                 rtnl_held);
2322                 if (IS_ERR(tp)) {
2323                         err = PTR_ERR(tp);
2324                         goto errout_tp;
2325                 }
2326         } else {
2327                 mutex_unlock(&chain->filter_chain_lock);
2328         }
2329
2330         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2331                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2332                 err = -EINVAL;
2333                 goto errout;
2334         }
2335
2336         fh = tp->ops->get(tp, t->tcm_handle);
2337
2338         if (!fh) {
2339                 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2340                         NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2341                         err = -ENOENT;
2342                         goto errout;
2343                 }
2344         } else if (n->nlmsg_flags & NLM_F_EXCL) {
2345                 tfilter_put(tp, fh);
2346                 NL_SET_ERR_MSG(extack, "Filter already exists");
2347                 err = -EEXIST;
2348                 goto errout;
2349         }
2350
2351         if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2352                 tfilter_put(tp, fh);
2353                 NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2354                 err = -EINVAL;
2355                 goto errout;
2356         }
2357
2358         if (!(n->nlmsg_flags & NLM_F_CREATE))
2359                 flags |= TCA_ACT_FLAGS_REPLACE;
2360         if (!rtnl_held)
2361                 flags |= TCA_ACT_FLAGS_NO_RTNL;
2362         if (is_qdisc_ingress(parent))
2363                 flags |= TCA_ACT_FLAGS_AT_INGRESS;
2364         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2365                               flags, extack);
2366         if (err == 0) {
2367                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2368                                RTM_NEWTFILTER, false, rtnl_held, extack);
2369                 tfilter_put(tp, fh);
2370                 /* q pointer is NULL for shared blocks */
2371                 if (q)
2372                         q->flags &= ~TCQ_F_CAN_BYPASS;
2373         }
2374
2375 errout:
2376         if (err && tp_created)
2377                 tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2378 errout_tp:
2379         if (chain) {
2380                 if (tp && !IS_ERR(tp))
2381                         tcf_proto_put(tp, rtnl_held, NULL);
2382                 if (!tp_created)
2383                         tcf_chain_put(chain);
2384         }
2385         tcf_block_release(q, block, rtnl_held);
2386
2387         if (rtnl_held)
2388                 rtnl_unlock();
2389
2390         if (err == -EAGAIN) {
2391                 /* Take rtnl lock in case EAGAIN is caused by concurrent flush
2392                  * of target chain.
2393                  */
2394                 rtnl_held = true;
2395                 /* Replay the request. */
2396                 goto replay;
2397         }
2398         return err;
2399
2400 errout_locked:
2401         mutex_unlock(&chain->filter_chain_lock);
2402         goto errout;
2403 }
2404
2405 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2406                           struct netlink_ext_ack *extack)
2407 {
2408         struct net *net = sock_net(skb->sk);
2409         struct nlattr *tca[TCA_MAX + 1];
2410         char name[IFNAMSIZ];
2411         struct tcmsg *t;
2412         u32 protocol;
2413         u32 prio;
2414         u32 parent;
2415         u32 chain_index;
2416         struct Qdisc *q = NULL;
2417         struct tcf_chain_info chain_info;
2418         struct tcf_chain *chain = NULL;
2419         struct tcf_block *block = NULL;
2420         struct tcf_proto *tp = NULL;
2421         unsigned long cl = 0;
2422         void *fh = NULL;
2423         int err;
2424         bool rtnl_held = false;
2425
2426         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2427                                      rtm_tca_policy, extack);
2428         if (err < 0)
2429                 return err;
2430
2431         t = nlmsg_data(n);
2432         protocol = TC_H_MIN(t->tcm_info);
2433         prio = TC_H_MAJ(t->tcm_info);
2434         parent = t->tcm_parent;
2435
2436         if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2437                 NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2438                 return -ENOENT;
2439         }
2440
2441         /* Find head of filter chain. */
2442
2443         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2444         if (err)
2445                 return err;
2446
2447         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2448                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2449                 err = -EINVAL;
2450                 goto errout;
2451         }
2452         /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2453          * found), qdisc is not unlocked, classifier type is not specified,
2454          * classifier is not unlocked.
2455          */
2456         if (!prio ||
2457             (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2458             !tcf_proto_is_unlocked(name)) {
2459                 rtnl_held = true;
2460                 rtnl_lock();
2461         }
2462
2463         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2464         if (err)
2465                 goto errout;
2466
2467         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2468                                  extack);
2469         if (IS_ERR(block)) {
2470                 err = PTR_ERR(block);
2471                 goto errout;
2472         }
2473
2474         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2475         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2476                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2477                 err = -EINVAL;
2478                 goto errout;
2479         }
2480         chain = tcf_chain_get(block, chain_index, false);
2481         if (!chain) {
2482                 /* User requested flush on non-existent chain. Nothing to do,
2483                  * so just return success.
2484                  */
2485                 if (prio == 0) {
2486                         err = 0;
2487                         goto errout;
2488                 }
2489                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2490                 err = -ENOENT;
2491                 goto errout;
2492         }
2493
2494         if (prio == 0) {
2495                 tfilter_notify_chain(net, skb, block, q, parent, n,
2496                                      chain, RTM_DELTFILTER, extack);
2497                 tcf_chain_flush(chain, rtnl_held);
2498                 err = 0;
2499                 goto errout;
2500         }
2501
2502         mutex_lock(&chain->filter_chain_lock);
2503         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2504                                prio, false);
2505         if (!tp || IS_ERR(tp)) {
2506                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2507                 err = tp ? PTR_ERR(tp) : -ENOENT;
2508                 goto errout_locked;
2509         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2510                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2511                 err = -EINVAL;
2512                 goto errout_locked;
2513         } else if (t->tcm_handle == 0) {
2514                 tcf_proto_signal_destroying(chain, tp);
2515                 tcf_chain_tp_remove(chain, &chain_info, tp);
2516                 mutex_unlock(&chain->filter_chain_lock);
2517
2518                 tcf_proto_put(tp, rtnl_held, NULL);
2519                 tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2520                                RTM_DELTFILTER, false, rtnl_held, extack);
2521                 err = 0;
2522                 goto errout;
2523         }
2524         mutex_unlock(&chain->filter_chain_lock);
2525
2526         fh = tp->ops->get(tp, t->tcm_handle);
2527
2528         if (!fh) {
2529                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2530                 err = -ENOENT;
2531         } else {
2532                 bool last;
2533
2534                 err = tfilter_del_notify(net, skb, n, tp, block, q, parent, fh,
2535                                          &last, rtnl_held, extack);
2536
2537                 if (err)
2538                         goto errout;
2539                 if (last)
2540                         tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2541         }
2542
2543 errout:
2544         if (chain) {
2545                 if (tp && !IS_ERR(tp))
2546                         tcf_proto_put(tp, rtnl_held, NULL);
2547                 tcf_chain_put(chain);
2548         }
2549         tcf_block_release(q, block, rtnl_held);
2550
2551         if (rtnl_held)
2552                 rtnl_unlock();
2553
2554         return err;
2555
2556 errout_locked:
2557         mutex_unlock(&chain->filter_chain_lock);
2558         goto errout;
2559 }
2560
2561 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2562                           struct netlink_ext_ack *extack)
2563 {
2564         struct net *net = sock_net(skb->sk);
2565         struct nlattr *tca[TCA_MAX + 1];
2566         char name[IFNAMSIZ];
2567         struct tcmsg *t;
2568         u32 protocol;
2569         u32 prio;
2570         u32 parent;
2571         u32 chain_index;
2572         struct Qdisc *q = NULL;
2573         struct tcf_chain_info chain_info;
2574         struct tcf_chain *chain = NULL;
2575         struct tcf_block *block = NULL;
2576         struct tcf_proto *tp = NULL;
2577         unsigned long cl = 0;
2578         void *fh = NULL;
2579         int err;
2580         bool rtnl_held = false;
2581
2582         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2583                                      rtm_tca_policy, extack);
2584         if (err < 0)
2585                 return err;
2586
2587         t = nlmsg_data(n);
2588         protocol = TC_H_MIN(t->tcm_info);
2589         prio = TC_H_MAJ(t->tcm_info);
2590         parent = t->tcm_parent;
2591
2592         if (prio == 0) {
2593                 NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2594                 return -ENOENT;
2595         }
2596
2597         /* Find head of filter chain. */
2598
2599         err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2600         if (err)
2601                 return err;
2602
2603         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
2604                 NL_SET_ERR_MSG(extack, "Specified TC filter name too long");
2605                 err = -EINVAL;
2606                 goto errout;
2607         }
2608         /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2609          * unlocked, classifier type is not specified, classifier is not
2610          * unlocked.
2611          */
2612         if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2613             !tcf_proto_is_unlocked(name)) {
2614                 rtnl_held = true;
2615                 rtnl_lock();
2616         }
2617
2618         err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2619         if (err)
2620                 goto errout;
2621
2622         block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2623                                  extack);
2624         if (IS_ERR(block)) {
2625                 err = PTR_ERR(block);
2626                 goto errout;
2627         }
2628
2629         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2630         if (chain_index > TC_ACT_EXT_VAL_MASK) {
2631                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2632                 err = -EINVAL;
2633                 goto errout;
2634         }
2635         chain = tcf_chain_get(block, chain_index, false);
2636         if (!chain) {
2637                 NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2638                 err = -EINVAL;
2639                 goto errout;
2640         }
2641
2642         mutex_lock(&chain->filter_chain_lock);
2643         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2644                                prio, false);
2645         mutex_unlock(&chain->filter_chain_lock);
2646         if (!tp || IS_ERR(tp)) {
2647                 NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2648                 err = tp ? PTR_ERR(tp) : -ENOENT;
2649                 goto errout;
2650         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2651                 NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2652                 err = -EINVAL;
2653                 goto errout;
2654         }
2655
2656         fh = tp->ops->get(tp, t->tcm_handle);
2657
2658         if (!fh) {
2659                 NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2660                 err = -ENOENT;
2661         } else {
2662                 err = tfilter_notify(net, skb, n, tp, block, q, parent,
2663                                      fh, RTM_NEWTFILTER, true, rtnl_held, NULL);
2664                 if (err < 0)
2665                         NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2666         }
2667
2668         tfilter_put(tp, fh);
2669 errout:
2670         if (chain) {
2671                 if (tp && !IS_ERR(tp))
2672                         tcf_proto_put(tp, rtnl_held, NULL);
2673                 tcf_chain_put(chain);
2674         }
2675         tcf_block_release(q, block, rtnl_held);
2676
2677         if (rtnl_held)
2678                 rtnl_unlock();
2679
2680         return err;
2681 }
2682
2683 struct tcf_dump_args {
2684         struct tcf_walker w;
2685         struct sk_buff *skb;
2686         struct netlink_callback *cb;
2687         struct tcf_block *block;
2688         struct Qdisc *q;
2689         u32 parent;
2690         bool terse_dump;
2691 };
2692
2693 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2694 {
2695         struct tcf_dump_args *a = (void *)arg;
2696         struct net *net = sock_net(a->skb->sk);
2697
2698         return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2699                              n, NETLINK_CB(a->cb->skb).portid,
2700                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2701                              RTM_NEWTFILTER, a->terse_dump, true, NULL);
2702 }
2703
2704 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2705                            struct sk_buff *skb, struct netlink_callback *cb,
2706                            long index_start, long *p_index, bool terse)
2707 {
2708         struct net *net = sock_net(skb->sk);
2709         struct tcf_block *block = chain->block;
2710         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2711         struct tcf_proto *tp, *tp_prev;
2712         struct tcf_dump_args arg;
2713
2714         for (tp = __tcf_get_next_proto(chain, NULL);
2715              tp;
2716              tp_prev = tp,
2717                      tp = __tcf_get_next_proto(chain, tp),
2718                      tcf_proto_put(tp_prev, true, NULL),
2719                      (*p_index)++) {
2720                 if (*p_index < index_start)
2721                         continue;
2722                 if (TC_H_MAJ(tcm->tcm_info) &&
2723                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
2724                         continue;
2725                 if (TC_H_MIN(tcm->tcm_info) &&
2726                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
2727                         continue;
2728                 if (*p_index > index_start)
2729                         memset(&cb->args[1], 0,
2730                                sizeof(cb->args) - sizeof(cb->args[0]));
2731                 if (cb->args[1] == 0) {
2732                         if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2733                                           NETLINK_CB(cb->skb).portid,
2734                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
2735                                           RTM_NEWTFILTER, false, true, NULL) <= 0)
2736                                 goto errout;
2737                         cb->args[1] = 1;
2738                 }
2739                 if (!tp->ops->walk)
2740                         continue;
2741                 arg.w.fn = tcf_node_dump;
2742                 arg.skb = skb;
2743                 arg.cb = cb;
2744                 arg.block = block;
2745                 arg.q = q;
2746                 arg.parent = parent;
2747                 arg.w.stop = 0;
2748                 arg.w.skip = cb->args[1] - 1;
2749                 arg.w.count = 0;
2750                 arg.w.cookie = cb->args[2];
2751                 arg.terse_dump = terse;
2752                 tp->ops->walk(tp, &arg.w, true);
2753                 cb->args[2] = arg.w.cookie;
2754                 cb->args[1] = arg.w.count + 1;
2755                 if (arg.w.stop)
2756                         goto errout;
2757         }
2758         return true;
2759
2760 errout:
2761         tcf_proto_put(tp, true, NULL);
2762         return false;
2763 }
2764
2765 static const struct nla_policy tcf_tfilter_dump_policy[TCA_MAX + 1] = {
2766         [TCA_CHAIN]      = { .type = NLA_U32 },
2767         [TCA_DUMP_FLAGS] = NLA_POLICY_BITFIELD32(TCA_DUMP_FLAGS_TERSE),
2768 };
2769
2770 /* called with RTNL */
2771 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2772 {
2773         struct tcf_chain *chain, *chain_prev;
2774         struct net *net = sock_net(skb->sk);
2775         struct nlattr *tca[TCA_MAX + 1];
2776         struct Qdisc *q = NULL;
2777         struct tcf_block *block;
2778         struct tcmsg *tcm = nlmsg_data(cb->nlh);
2779         bool terse_dump = false;
2780         long index_start;
2781         long index;
2782         u32 parent;
2783         int err;
2784
2785         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2786                 return skb->len;
2787
2788         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2789                                      tcf_tfilter_dump_policy, cb->extack);
2790         if (err)
2791                 return err;
2792
2793         if (tca[TCA_DUMP_FLAGS]) {
2794                 struct nla_bitfield32 flags =
2795                         nla_get_bitfield32(tca[TCA_DUMP_FLAGS]);
2796
2797                 terse_dump = flags.value & TCA_DUMP_FLAGS_TERSE;
2798         }
2799
2800         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2801                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2802                 if (!block)
2803                         goto out;
2804                 /* If we work with block index, q is NULL and parent value
2805                  * will never be used in the following code. The check
2806                  * in tcf_fill_node prevents it. However, compiler does not
2807                  * see that far, so set parent to zero to silence the warning
2808                  * about parent being uninitialized.
2809                  */
2810                 parent = 0;
2811         } else {
2812                 const struct Qdisc_class_ops *cops;
2813                 struct net_device *dev;
2814                 unsigned long cl = 0;
2815
2816                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2817                 if (!dev)
2818                         return skb->len;
2819
2820                 parent = tcm->tcm_parent;
2821                 if (!parent)
2822                         q = rtnl_dereference(dev->qdisc);
2823                 else
2824                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2825                 if (!q)
2826                         goto out;
2827                 cops = q->ops->cl_ops;
2828                 if (!cops)
2829                         goto out;
2830                 if (!cops->tcf_block)
2831                         goto out;
2832                 if (TC_H_MIN(tcm->tcm_parent)) {
2833                         cl = cops->find(q, tcm->tcm_parent);
2834                         if (cl == 0)
2835                                 goto out;
2836                 }
2837                 block = cops->tcf_block(q, cl, NULL);
2838                 if (!block)
2839                         goto out;
2840                 parent = block->classid;
2841                 if (tcf_block_shared(block))
2842                         q = NULL;
2843         }
2844
2845         index_start = cb->args[0];
2846         index = 0;
2847
2848         for (chain = __tcf_get_next_chain(block, NULL);
2849              chain;
2850              chain_prev = chain,
2851                      chain = __tcf_get_next_chain(block, chain),
2852                      tcf_chain_put(chain_prev)) {
2853                 if (tca[TCA_CHAIN] &&
2854                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2855                         continue;
2856                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
2857                                     index_start, &index, terse_dump)) {
2858                         tcf_chain_put(chain);
2859                         err = -EMSGSIZE;
2860                         break;
2861                 }
2862         }
2863
2864         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2865                 tcf_block_refcnt_put(block, true);
2866         cb->args[0] = index;
2867
2868 out:
2869         /* If we did no progress, the error (EMSGSIZE) is real */
2870         if (skb->len == 0 && err)
2871                 return err;
2872         return skb->len;
2873 }
2874
2875 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2876                               void *tmplt_priv, u32 chain_index,
2877                               struct net *net, struct sk_buff *skb,
2878                               struct tcf_block *block,
2879                               u32 portid, u32 seq, u16 flags, int event,
2880                               struct netlink_ext_ack *extack)
2881 {
2882         unsigned char *b = skb_tail_pointer(skb);
2883         const struct tcf_proto_ops *ops;
2884         struct nlmsghdr *nlh;
2885         struct tcmsg *tcm;
2886         void *priv;
2887
2888         ops = tmplt_ops;
2889         priv = tmplt_priv;
2890
2891         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2892         if (!nlh)
2893                 goto out_nlmsg_trim;
2894         tcm = nlmsg_data(nlh);
2895         tcm->tcm_family = AF_UNSPEC;
2896         tcm->tcm__pad1 = 0;
2897         tcm->tcm__pad2 = 0;
2898         tcm->tcm_handle = 0;
2899         if (block->q) {
2900                 tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2901                 tcm->tcm_parent = block->q->handle;
2902         } else {
2903                 tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2904                 tcm->tcm_block_index = block->index;
2905         }
2906
2907         if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2908                 goto nla_put_failure;
2909
2910         if (ops) {
2911                 if (nla_put_string(skb, TCA_KIND, ops->kind))
2912                         goto nla_put_failure;
2913                 if (ops->tmplt_dump(skb, net, priv) < 0)
2914                         goto nla_put_failure;
2915         }
2916
2917         if (extack && extack->_msg &&
2918             nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
2919                 goto out_nlmsg_trim;
2920
2921         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2922
2923         return skb->len;
2924
2925 out_nlmsg_trim:
2926 nla_put_failure:
2927         nlmsg_trim(skb, b);
2928         return -EMSGSIZE;
2929 }
2930
2931 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2932                            u32 seq, u16 flags, int event, bool unicast,
2933                            struct netlink_ext_ack *extack)
2934 {
2935         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2936         struct tcf_block *block = chain->block;
2937         struct net *net = block->net;
2938         struct sk_buff *skb;
2939         int err = 0;
2940
2941         if (!unicast && !rtnl_notify_needed(net, flags, RTNLGRP_TC))
2942                 return 0;
2943
2944         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2945         if (!skb)
2946                 return -ENOBUFS;
2947
2948         if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2949                                chain->index, net, skb, block, portid,
2950                                seq, flags, event, extack) <= 0) {
2951                 kfree_skb(skb);
2952                 return -EINVAL;
2953         }
2954
2955         if (unicast)
2956                 err = rtnl_unicast(skb, net, portid);
2957         else
2958                 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2959                                      flags & NLM_F_ECHO);
2960
2961         return err;
2962 }
2963
2964 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2965                                   void *tmplt_priv, u32 chain_index,
2966                                   struct tcf_block *block, struct sk_buff *oskb,
2967                                   u32 seq, u16 flags)
2968 {
2969         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2970         struct net *net = block->net;
2971         struct sk_buff *skb;
2972
2973         if (!rtnl_notify_needed(net, flags, RTNLGRP_TC))
2974                 return 0;
2975
2976         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2977         if (!skb)
2978                 return -ENOBUFS;
2979
2980         if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2981                                block, portid, seq, flags, RTM_DELCHAIN, NULL) <= 0) {
2982                 kfree_skb(skb);
2983                 return -EINVAL;
2984         }
2985
2986         return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2987 }
2988
2989 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2990                               struct nlattr **tca,
2991                               struct netlink_ext_ack *extack)
2992 {
2993         const struct tcf_proto_ops *ops;
2994         char name[IFNAMSIZ];
2995         void *tmplt_priv;
2996
2997         /* If kind is not set, user did not specify template. */
2998         if (!tca[TCA_KIND])
2999                 return 0;
3000
3001         if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
3002                 NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
3003                 return -EINVAL;
3004         }
3005
3006         ops = tcf_proto_lookup_ops(name, true, extack);
3007         if (IS_ERR(ops))
3008                 return PTR_ERR(ops);
3009         if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump ||
3010             !ops->tmplt_reoffload) {
3011                 NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
3012                 module_put(ops->owner);
3013                 return -EOPNOTSUPP;
3014         }
3015
3016         tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
3017         if (IS_ERR(tmplt_priv)) {
3018                 module_put(ops->owner);
3019                 return PTR_ERR(tmplt_priv);
3020         }
3021         chain->tmplt_ops = ops;
3022         chain->tmplt_priv = tmplt_priv;
3023         return 0;
3024 }
3025
3026 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
3027                                void *tmplt_priv)
3028 {
3029         /* If template ops are set, no work to do for us. */
3030         if (!tmplt_ops)
3031                 return;
3032
3033         tmplt_ops->tmplt_destroy(tmplt_priv);
3034         module_put(tmplt_ops->owner);
3035 }
3036
3037 /* Add/delete/get a chain */
3038
3039 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
3040                         struct netlink_ext_ack *extack)
3041 {
3042         struct net *net = sock_net(skb->sk);
3043         struct nlattr *tca[TCA_MAX + 1];
3044         struct tcmsg *t;
3045         u32 parent;
3046         u32 chain_index;
3047         struct Qdisc *q;
3048         struct tcf_chain *chain;
3049         struct tcf_block *block;
3050         unsigned long cl;
3051         int err;
3052
3053 replay:
3054         q = NULL;
3055         err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
3056                                      rtm_tca_policy, extack);
3057         if (err < 0)
3058                 return err;
3059
3060         t = nlmsg_data(n);
3061         parent = t->tcm_parent;
3062         cl = 0;
3063
3064         block = tcf_block_find(net, &q, &parent, &cl,
3065                                t->tcm_ifindex, t->tcm_block_index, extack);
3066         if (IS_ERR(block))
3067                 return PTR_ERR(block);
3068
3069         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
3070         if (chain_index > TC_ACT_EXT_VAL_MASK) {
3071                 NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
3072                 err = -EINVAL;
3073                 goto errout_block;
3074         }
3075
3076         mutex_lock(&block->lock);
3077         chain = tcf_chain_lookup(block, chain_index);
3078         if (n->nlmsg_type == RTM_NEWCHAIN) {
3079                 if (chain) {
3080                         if (tcf_chain_held_by_acts_only(chain)) {
3081                                 /* The chain exists only because there is
3082                                  * some action referencing it.
3083                                  */
3084                                 tcf_chain_hold(chain);
3085                         } else {
3086                                 NL_SET_ERR_MSG(extack, "Filter chain already exists");
3087                                 err = -EEXIST;
3088                                 goto errout_block_locked;
3089                         }
3090                 } else {
3091                         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
3092                                 NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
3093                                 err = -ENOENT;
3094                                 goto errout_block_locked;
3095                         }
3096                         chain = tcf_chain_create(block, chain_index);
3097                         if (!chain) {
3098                                 NL_SET_ERR_MSG(extack, "Failed to create filter chain");
3099                                 err = -ENOMEM;
3100                                 goto errout_block_locked;
3101                         }
3102                 }
3103         } else {
3104                 if (!chain || tcf_chain_held_by_acts_only(chain)) {
3105                         NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
3106                         err = -EINVAL;
3107                         goto errout_block_locked;
3108                 }
3109                 tcf_chain_hold(chain);
3110         }
3111
3112         if (n->nlmsg_type == RTM_NEWCHAIN) {
3113                 /* Modifying chain requires holding parent block lock. In case
3114                  * the chain was successfully added, take a reference to the
3115                  * chain. This ensures that an empty chain does not disappear at
3116                  * the end of this function.
3117                  */
3118                 tcf_chain_hold(chain);
3119                 chain->explicitly_created = true;
3120         }
3121         mutex_unlock(&block->lock);
3122
3123         switch (n->nlmsg_type) {
3124         case RTM_NEWCHAIN:
3125                 err = tc_chain_tmplt_add(chain, net, tca, extack);
3126                 if (err) {
3127                         tcf_chain_put_explicitly_created(chain);
3128                         goto errout;
3129                 }
3130
3131                 tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
3132                                 RTM_NEWCHAIN, false, extack);
3133                 break;
3134         case RTM_DELCHAIN:
3135                 tfilter_notify_chain(net, skb, block, q, parent, n,
3136                                      chain, RTM_DELTFILTER, extack);
3137                 /* Flush the chain first as the user requested chain removal. */
3138                 tcf_chain_flush(chain, true);
3139                 /* In case the chain was successfully deleted, put a reference
3140                  * to the chain previously taken during addition.
3141                  */
3142                 tcf_chain_put_explicitly_created(chain);
3143                 break;
3144         case RTM_GETCHAIN:
3145                 err = tc_chain_notify(chain, skb, n->nlmsg_seq,
3146                                       n->nlmsg_flags, n->nlmsg_type, true, extack);
3147                 if (err < 0)
3148                         NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
3149                 break;
3150         default:
3151                 err = -EOPNOTSUPP;
3152                 NL_SET_ERR_MSG(extack, "Unsupported message type");
3153                 goto errout;
3154         }
3155
3156 errout:
3157         tcf_chain_put(chain);
3158 errout_block:
3159         tcf_block_release(q, block, true);
3160         if (err == -EAGAIN)
3161                 /* Replay the request. */
3162                 goto replay;
3163         return err;
3164
3165 errout_block_locked:
3166         mutex_unlock(&block->lock);
3167         goto errout_block;
3168 }
3169
3170 /* called with RTNL */
3171 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
3172 {
3173         struct net *net = sock_net(skb->sk);
3174         struct nlattr *tca[TCA_MAX + 1];
3175         struct Qdisc *q = NULL;
3176         struct tcf_block *block;
3177         struct tcmsg *tcm = nlmsg_data(cb->nlh);
3178         struct tcf_chain *chain;
3179         long index_start;
3180         long index;
3181         int err;
3182
3183         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
3184                 return skb->len;
3185
3186         err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
3187                                      rtm_tca_policy, cb->extack);
3188         if (err)
3189                 return err;
3190
3191         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
3192                 block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
3193                 if (!block)
3194                         goto out;
3195         } else {
3196                 const struct Qdisc_class_ops *cops;
3197                 struct net_device *dev;
3198                 unsigned long cl = 0;
3199
3200                 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
3201                 if (!dev)
3202                         return skb->len;
3203
3204                 if (!tcm->tcm_parent)
3205                         q = rtnl_dereference(dev->qdisc);
3206                 else
3207                         q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
3208
3209                 if (!q)
3210                         goto out;
3211                 cops = q->ops->cl_ops;
3212                 if (!cops)
3213                         goto out;
3214                 if (!cops->tcf_block)
3215                         goto out;
3216                 if (TC_H_MIN(tcm->tcm_parent)) {
3217                         cl = cops->find(q, tcm->tcm_parent);
3218                         if (cl == 0)
3219                                 goto out;
3220                 }
3221                 block = cops->tcf_block(q, cl, NULL);
3222                 if (!block)
3223                         goto out;
3224                 if (tcf_block_shared(block))
3225                         q = NULL;
3226         }
3227
3228         index_start = cb->args[0];
3229         index = 0;
3230
3231         mutex_lock(&block->lock);
3232         list_for_each_entry(chain, &block->chain_list, list) {
3233                 if ((tca[TCA_CHAIN] &&
3234                      nla_get_u32(tca[TCA_CHAIN]) != chain->index))
3235                         continue;
3236                 if (index < index_start) {
3237                         index++;
3238                         continue;
3239                 }
3240                 if (tcf_chain_held_by_acts_only(chain))
3241                         continue;
3242                 err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3243                                          chain->index, net, skb, block,
3244                                          NETLINK_CB(cb->skb).portid,
3245                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
3246                                          RTM_NEWCHAIN, NULL);
3247                 if (err <= 0)
3248                         break;
3249                 index++;
3250         }
3251         mutex_unlock(&block->lock);
3252
3253         if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3254                 tcf_block_refcnt_put(block, true);
3255         cb->args[0] = index;
3256
3257 out:
3258         /* If we did no progress, the error (EMSGSIZE) is real */
3259         if (skb->len == 0 && err)
3260                 return err;
3261         return skb->len;
3262 }
3263
3264 int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
3265                      int police, struct tcf_proto *tp, u32 handle,
3266                      bool use_action_miss)
3267 {
3268         int err = 0;
3269
3270 #ifdef CONFIG_NET_CLS_ACT
3271         exts->type = 0;
3272         exts->nr_actions = 0;
3273         exts->miss_cookie_node = NULL;
3274         /* Note: we do not own yet a reference on net.
3275          * This reference might be taken later from tcf_exts_get_net().
3276          */
3277         exts->net = net;
3278         exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
3279                                 GFP_KERNEL);
3280         if (!exts->actions)
3281                 return -ENOMEM;
3282 #endif
3283
3284         exts->action = action;
3285         exts->police = police;
3286
3287         if (!use_action_miss)
3288                 return 0;
3289
3290         err = tcf_exts_miss_cookie_base_alloc(exts, tp, handle);
3291         if (err)
3292                 goto err_miss_alloc;
3293
3294         return 0;
3295
3296 err_miss_alloc:
3297         tcf_exts_destroy(exts);
3298 #ifdef CONFIG_NET_CLS_ACT
3299         exts->actions = NULL;
3300 #endif
3301         return err;
3302 }
3303 EXPORT_SYMBOL(tcf_exts_init_ex);
3304
3305 void tcf_exts_destroy(struct tcf_exts *exts)
3306 {
3307         tcf_exts_miss_cookie_base_destroy(exts);
3308
3309 #ifdef CONFIG_NET_CLS_ACT
3310         if (exts->actions) {
3311                 tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3312                 kfree(exts->actions);
3313         }
3314         exts->nr_actions = 0;
3315 #endif
3316 }
3317 EXPORT_SYMBOL(tcf_exts_destroy);
3318
3319 int tcf_exts_validate_ex(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3320                          struct nlattr *rate_tlv, struct tcf_exts *exts,
3321                          u32 flags, u32 fl_flags, struct netlink_ext_ack *extack)
3322 {
3323 #ifdef CONFIG_NET_CLS_ACT
3324         {
3325                 int init_res[TCA_ACT_MAX_PRIO] = {};
3326                 struct tc_action *act;
3327                 size_t attr_size = 0;
3328
3329                 if (exts->police && tb[exts->police]) {
3330                         struct tc_action_ops *a_o;
3331
3332                         flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
3333                         a_o = tc_action_load_ops(tb[exts->police], flags,
3334                                                  extack);
3335                         if (IS_ERR(a_o))
3336                                 return PTR_ERR(a_o);
3337                         act = tcf_action_init_1(net, tp, tb[exts->police],
3338                                                 rate_tlv, a_o, init_res, flags,
3339                                                 extack);
3340                         module_put(a_o->owner);
3341                         if (IS_ERR(act))
3342                                 return PTR_ERR(act);
3343
3344                         act->type = exts->type = TCA_OLD_COMPAT;
3345                         exts->actions[0] = act;
3346                         exts->nr_actions = 1;
3347                         tcf_idr_insert_many(exts->actions, init_res);
3348                 } else if (exts->action && tb[exts->action]) {
3349                         int err;
3350
3351                         flags |= TCA_ACT_FLAGS_BIND;
3352                         err = tcf_action_init(net, tp, tb[exts->action],
3353                                               rate_tlv, exts->actions, init_res,
3354                                               &attr_size, flags, fl_flags,
3355                                               extack);
3356                         if (err < 0)
3357                                 return err;
3358                         exts->nr_actions = err;
3359                 }
3360         }
3361 #else
3362         if ((exts->action && tb[exts->action]) ||
3363             (exts->police && tb[exts->police])) {
3364                 NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3365                 return -EOPNOTSUPP;
3366         }
3367 #endif
3368
3369         return 0;
3370 }
3371 EXPORT_SYMBOL(tcf_exts_validate_ex);
3372
3373 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3374                       struct nlattr *rate_tlv, struct tcf_exts *exts,
3375                       u32 flags, struct netlink_ext_ack *extack)
3376 {
3377         return tcf_exts_validate_ex(net, tp, tb, rate_tlv, exts,
3378                                     flags, 0, extack);
3379 }
3380 EXPORT_SYMBOL(tcf_exts_validate);
3381
3382 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3383 {
3384 #ifdef CONFIG_NET_CLS_ACT
3385         struct tcf_exts old = *dst;
3386
3387         *dst = *src;
3388         tcf_exts_destroy(&old);
3389 #endif
3390 }
3391 EXPORT_SYMBOL(tcf_exts_change);
3392
3393 #ifdef CONFIG_NET_CLS_ACT
3394 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3395 {
3396         if (exts->nr_actions == 0)
3397                 return NULL;
3398         else
3399                 return exts->actions[0];
3400 }
3401 #endif
3402
3403 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3404 {
3405 #ifdef CONFIG_NET_CLS_ACT
3406         struct nlattr *nest;
3407
3408         if (exts->action && tcf_exts_has_actions(exts)) {
3409                 /*
3410                  * again for backward compatible mode - we want
3411                  * to work with both old and new modes of entering
3412                  * tc data even if iproute2  was newer - jhs
3413                  */
3414                 if (exts->type != TCA_OLD_COMPAT) {
3415                         nest = nla_nest_start_noflag(skb, exts->action);
3416                         if (nest == NULL)
3417                                 goto nla_put_failure;
3418
3419                         if (tcf_action_dump(skb, exts->actions, 0, 0, false)
3420                             < 0)
3421                                 goto nla_put_failure;
3422                         nla_nest_end(skb, nest);
3423                 } else if (exts->police) {
3424                         struct tc_action *act = tcf_exts_first_act(exts);
3425                         nest = nla_nest_start_noflag(skb, exts->police);
3426                         if (nest == NULL || !act)
3427                                 goto nla_put_failure;
3428                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3429                                 goto nla_put_failure;
3430                         nla_nest_end(skb, nest);
3431                 }
3432         }
3433         return 0;
3434
3435 nla_put_failure:
3436         nla_nest_cancel(skb, nest);
3437         return -1;
3438 #else
3439         return 0;
3440 #endif
3441 }
3442 EXPORT_SYMBOL(tcf_exts_dump);
3443
3444 int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
3445 {
3446 #ifdef CONFIG_NET_CLS_ACT
3447         struct nlattr *nest;
3448
3449         if (!exts->action || !tcf_exts_has_actions(exts))
3450                 return 0;
3451
3452         nest = nla_nest_start_noflag(skb, exts->action);
3453         if (!nest)
3454                 goto nla_put_failure;
3455
3456         if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
3457                 goto nla_put_failure;
3458         nla_nest_end(skb, nest);
3459         return 0;
3460
3461 nla_put_failure:
3462         nla_nest_cancel(skb, nest);
3463         return -1;
3464 #else
3465         return 0;
3466 #endif
3467 }
3468 EXPORT_SYMBOL(tcf_exts_terse_dump);
3469
3470 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3471 {
3472 #ifdef CONFIG_NET_CLS_ACT
3473         struct tc_action *a = tcf_exts_first_act(exts);
3474         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3475                 return -1;
3476 #endif
3477         return 0;
3478 }
3479 EXPORT_SYMBOL(tcf_exts_dump_stats);
3480
3481 static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
3482 {
3483         if (*flags & TCA_CLS_FLAGS_IN_HW)
3484                 return;
3485         *flags |= TCA_CLS_FLAGS_IN_HW;
3486         atomic_inc(&block->offloadcnt);
3487 }
3488
3489 static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
3490 {
3491         if (!(*flags & TCA_CLS_FLAGS_IN_HW))
3492                 return;
3493         *flags &= ~TCA_CLS_FLAGS_IN_HW;
3494         atomic_dec(&block->offloadcnt);
3495 }
3496
3497 static void tc_cls_offload_cnt_update(struct tcf_block *block,
3498                                       struct tcf_proto *tp, u32 *cnt,
3499                                       u32 *flags, u32 diff, bool add)
3500 {
3501         lockdep_assert_held(&block->cb_lock);
3502
3503         spin_lock(&tp->lock);
3504         if (add) {
3505                 if (!*cnt)
3506                         tcf_block_offload_inc(block, flags);
3507                 *cnt += diff;
3508         } else {
3509                 *cnt -= diff;
3510                 if (!*cnt)
3511                         tcf_block_offload_dec(block, flags);
3512         }
3513         spin_unlock(&tp->lock);
3514 }
3515
3516 static void
3517 tc_cls_offload_cnt_reset(struct tcf_block *block, struct tcf_proto *tp,
3518                          u32 *cnt, u32 *flags)
3519 {
3520         lockdep_assert_held(&block->cb_lock);
3521
3522         spin_lock(&tp->lock);
3523         tcf_block_offload_dec(block, flags);
3524         *cnt = 0;
3525         spin_unlock(&tp->lock);
3526 }
3527
3528 static int
3529 __tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3530                    void *type_data, bool err_stop)
3531 {
3532         struct flow_block_cb *block_cb;
3533         int ok_count = 0;
3534         int err;
3535
3536         list_for_each_entry(block_cb, &block->flow_block.cb_list, list) {
3537                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
3538                 if (err) {
3539                         if (err_stop)
3540                                 return err;
3541                 } else {
3542                         ok_count++;
3543                 }
3544         }
3545         return ok_count;
3546 }
3547
3548 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3549                      void *type_data, bool err_stop, bool rtnl_held)
3550 {
3551         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3552         int ok_count;
3553
3554 retry:
3555         if (take_rtnl)
3556                 rtnl_lock();
3557         down_read(&block->cb_lock);
3558         /* Need to obtain rtnl lock if block is bound to devs that require it.
3559          * In block bind code cb_lock is obtained while holding rtnl, so we must
3560          * obtain the locks in same order here.
3561          */
3562         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3563                 up_read(&block->cb_lock);
3564                 take_rtnl = true;
3565                 goto retry;
3566         }
3567
3568         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3569
3570         up_read(&block->cb_lock);
3571         if (take_rtnl)
3572                 rtnl_unlock();
3573         return ok_count;
3574 }
3575 EXPORT_SYMBOL(tc_setup_cb_call);
3576
3577 /* Non-destructive filter add. If filter that wasn't already in hardware is
3578  * successfully offloaded, increment block offloads counter. On failure,
3579  * previously offloaded filter is considered to be intact and offloads counter
3580  * is not decremented.
3581  */
3582
3583 int tc_setup_cb_add(struct tcf_block *block, struct tcf_proto *tp,
3584                     enum tc_setup_type type, void *type_data, bool err_stop,
3585                     u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3586 {
3587         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3588         int ok_count;
3589
3590 retry:
3591         if (take_rtnl)
3592                 rtnl_lock();
3593         down_read(&block->cb_lock);
3594         /* Need to obtain rtnl lock if block is bound to devs that require it.
3595          * In block bind code cb_lock is obtained while holding rtnl, so we must
3596          * obtain the locks in same order here.
3597          */
3598         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3599                 up_read(&block->cb_lock);
3600                 take_rtnl = true;
3601                 goto retry;
3602         }
3603
3604         /* Make sure all netdevs sharing this block are offload-capable. */
3605         if (block->nooffloaddevcnt && err_stop) {
3606                 ok_count = -EOPNOTSUPP;
3607                 goto err_unlock;
3608         }
3609
3610         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3611         if (ok_count < 0)
3612                 goto err_unlock;
3613
3614         if (tp->ops->hw_add)
3615                 tp->ops->hw_add(tp, type_data);
3616         if (ok_count > 0)
3617                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags,
3618                                           ok_count, true);
3619 err_unlock:
3620         up_read(&block->cb_lock);
3621         if (take_rtnl)
3622                 rtnl_unlock();
3623         return min(ok_count, 0);
3624 }
3625 EXPORT_SYMBOL(tc_setup_cb_add);
3626
3627 /* Destructive filter replace. If filter that wasn't already in hardware is
3628  * successfully offloaded, increment block offload counter. On failure,
3629  * previously offloaded filter is considered to be destroyed and offload counter
3630  * is decremented.
3631  */
3632
3633 int tc_setup_cb_replace(struct tcf_block *block, struct tcf_proto *tp,
3634                         enum tc_setup_type type, void *type_data, bool err_stop,
3635                         u32 *old_flags, unsigned int *old_in_hw_count,
3636                         u32 *new_flags, unsigned int *new_in_hw_count,
3637                         bool rtnl_held)
3638 {
3639         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3640         int ok_count;
3641
3642 retry:
3643         if (take_rtnl)
3644                 rtnl_lock();
3645         down_read(&block->cb_lock);
3646         /* Need to obtain rtnl lock if block is bound to devs that require it.
3647          * In block bind code cb_lock is obtained while holding rtnl, so we must
3648          * obtain the locks in same order here.
3649          */
3650         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3651                 up_read(&block->cb_lock);
3652                 take_rtnl = true;
3653                 goto retry;
3654         }
3655
3656         /* Make sure all netdevs sharing this block are offload-capable. */
3657         if (block->nooffloaddevcnt && err_stop) {
3658                 ok_count = -EOPNOTSUPP;
3659                 goto err_unlock;
3660         }
3661
3662         tc_cls_offload_cnt_reset(block, tp, old_in_hw_count, old_flags);
3663         if (tp->ops->hw_del)
3664                 tp->ops->hw_del(tp, type_data);
3665
3666         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3667         if (ok_count < 0)
3668                 goto err_unlock;
3669
3670         if (tp->ops->hw_add)
3671                 tp->ops->hw_add(tp, type_data);
3672         if (ok_count > 0)
3673                 tc_cls_offload_cnt_update(block, tp, new_in_hw_count,
3674                                           new_flags, ok_count, true);
3675 err_unlock:
3676         up_read(&block->cb_lock);
3677         if (take_rtnl)
3678                 rtnl_unlock();
3679         return min(ok_count, 0);
3680 }
3681 EXPORT_SYMBOL(tc_setup_cb_replace);
3682
3683 /* Destroy filter and decrement block offload counter, if filter was previously
3684  * offloaded.
3685  */
3686
3687 int tc_setup_cb_destroy(struct tcf_block *block, struct tcf_proto *tp,
3688                         enum tc_setup_type type, void *type_data, bool err_stop,
3689                         u32 *flags, unsigned int *in_hw_count, bool rtnl_held)
3690 {
3691         bool take_rtnl = READ_ONCE(block->lockeddevcnt) && !rtnl_held;
3692         int ok_count;
3693
3694 retry:
3695         if (take_rtnl)
3696                 rtnl_lock();
3697         down_read(&block->cb_lock);
3698         /* Need to obtain rtnl lock if block is bound to devs that require it.
3699          * In block bind code cb_lock is obtained while holding rtnl, so we must
3700          * obtain the locks in same order here.
3701          */
3702         if (!rtnl_held && !take_rtnl && block->lockeddevcnt) {
3703                 up_read(&block->cb_lock);
3704                 take_rtnl = true;
3705                 goto retry;
3706         }
3707
3708         ok_count = __tc_setup_cb_call(block, type, type_data, err_stop);
3709
3710         tc_cls_offload_cnt_reset(block, tp, in_hw_count, flags);
3711         if (tp->ops->hw_del)
3712                 tp->ops->hw_del(tp, type_data);
3713
3714         up_read(&block->cb_lock);
3715         if (take_rtnl)
3716                 rtnl_unlock();
3717         return min(ok_count, 0);
3718 }
3719 EXPORT_SYMBOL(tc_setup_cb_destroy);
3720
3721 int tc_setup_cb_reoffload(struct tcf_block *block, struct tcf_proto *tp,
3722                           bool add, flow_setup_cb_t *cb,
3723                           enum tc_setup_type type, void *type_data,
3724                           void *cb_priv, u32 *flags, unsigned int *in_hw_count)
3725 {
3726         int err = cb(type, type_data, cb_priv);
3727
3728         if (err) {
3729                 if (add && tc_skip_sw(*flags))
3730                         return err;
3731         } else {
3732                 tc_cls_offload_cnt_update(block, tp, in_hw_count, flags, 1,
3733                                           add);
3734         }
3735
3736         return 0;
3737 }
3738 EXPORT_SYMBOL(tc_setup_cb_reoffload);
3739
3740 static int tcf_act_get_user_cookie(struct flow_action_entry *entry,
3741                                    const struct tc_action *act)
3742 {
3743         struct tc_cookie *user_cookie;
3744         int err = 0;
3745
3746         rcu_read_lock();
3747         user_cookie = rcu_dereference(act->user_cookie);
3748         if (user_cookie) {
3749                 entry->user_cookie = flow_action_cookie_create(user_cookie->data,
3750                                                                user_cookie->len,
3751                                                                GFP_ATOMIC);
3752                 if (!entry->user_cookie)
3753                         err = -ENOMEM;
3754         }
3755         rcu_read_unlock();
3756         return err;
3757 }
3758
3759 static void tcf_act_put_user_cookie(struct flow_action_entry *entry)
3760 {
3761         flow_action_cookie_destroy(entry->user_cookie);
3762 }
3763
3764 void tc_cleanup_offload_action(struct flow_action *flow_action)
3765 {
3766         struct flow_action_entry *entry;
3767         int i;
3768
3769         flow_action_for_each(i, entry, flow_action) {
3770                 tcf_act_put_user_cookie(entry);
3771                 if (entry->destructor)
3772                         entry->destructor(entry->destructor_priv);
3773         }
3774 }
3775 EXPORT_SYMBOL(tc_cleanup_offload_action);
3776
3777 static int tc_setup_offload_act(struct tc_action *act,
3778                                 struct flow_action_entry *entry,
3779                                 u32 *index_inc,
3780                                 struct netlink_ext_ack *extack)
3781 {
3782 #ifdef CONFIG_NET_CLS_ACT
3783         if (act->ops->offload_act_setup) {
3784                 return act->ops->offload_act_setup(act, entry, index_inc, true,
3785                                                    extack);
3786         } else {
3787                 NL_SET_ERR_MSG(extack, "Action does not support offload");
3788                 return -EOPNOTSUPP;
3789         }
3790 #else
3791         return 0;
3792 #endif
3793 }
3794
3795 int tc_setup_action(struct flow_action *flow_action,
3796                     struct tc_action *actions[],
3797                     u32 miss_cookie_base,
3798                     struct netlink_ext_ack *extack)
3799 {
3800         int i, j, k, index, err = 0;
3801         struct tc_action *act;
3802
3803         BUILD_BUG_ON(TCA_ACT_HW_STATS_ANY != FLOW_ACTION_HW_STATS_ANY);
3804         BUILD_BUG_ON(TCA_ACT_HW_STATS_IMMEDIATE != FLOW_ACTION_HW_STATS_IMMEDIATE);
3805         BUILD_BUG_ON(TCA_ACT_HW_STATS_DELAYED != FLOW_ACTION_HW_STATS_DELAYED);
3806
3807         if (!actions)
3808                 return 0;
3809
3810         j = 0;
3811         tcf_act_for_each_action(i, act, actions) {
3812                 struct flow_action_entry *entry;
3813
3814                 entry = &flow_action->entries[j];
3815                 spin_lock_bh(&act->tcfa_lock);
3816                 err = tcf_act_get_user_cookie(entry, act);
3817                 if (err)
3818                         goto err_out_locked;
3819
3820                 index = 0;
3821                 err = tc_setup_offload_act(act, entry, &index, extack);
3822                 if (err)
3823                         goto err_out_locked;
3824
3825                 for (k = 0; k < index ; k++) {
3826                         entry[k].hw_stats = tc_act_hw_stats(act->hw_stats);
3827                         entry[k].hw_index = act->tcfa_index;
3828                         entry[k].cookie = (unsigned long)act;
3829                         entry[k].miss_cookie =
3830                                 tcf_exts_miss_cookie_get(miss_cookie_base, i);
3831                 }
3832
3833                 j += index;
3834
3835                 spin_unlock_bh(&act->tcfa_lock);
3836         }
3837
3838 err_out:
3839         if (err)
3840                 tc_cleanup_offload_action(flow_action);
3841
3842         return err;
3843 err_out_locked:
3844         spin_unlock_bh(&act->tcfa_lock);
3845         goto err_out;
3846 }
3847
3848 int tc_setup_offload_action(struct flow_action *flow_action,
3849                             const struct tcf_exts *exts,
3850                             struct netlink_ext_ack *extack)
3851 {
3852 #ifdef CONFIG_NET_CLS_ACT
3853         u32 miss_cookie_base;
3854
3855         if (!exts)
3856                 return 0;
3857
3858         miss_cookie_base = exts->miss_cookie_node ?
3859                            exts->miss_cookie_node->miss_cookie_base : 0;
3860         return tc_setup_action(flow_action, exts->actions, miss_cookie_base,
3861                                extack);
3862 #else
3863         return 0;
3864 #endif
3865 }
3866 EXPORT_SYMBOL(tc_setup_offload_action);
3867
3868 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3869 {
3870         unsigned int num_acts = 0;
3871         struct tc_action *act;
3872         int i;
3873
3874         tcf_exts_for_each_action(i, act, exts) {
3875                 if (is_tcf_pedit(act))
3876                         num_acts += tcf_pedit_nkeys(act);
3877                 else
3878                         num_acts++;
3879         }
3880         return num_acts;
3881 }
3882 EXPORT_SYMBOL(tcf_exts_num_actions);
3883
3884 #ifdef CONFIG_NET_CLS_ACT
3885 static int tcf_qevent_parse_block_index(struct nlattr *block_index_attr,
3886                                         u32 *p_block_index,
3887                                         struct netlink_ext_ack *extack)
3888 {
3889         *p_block_index = nla_get_u32(block_index_attr);
3890         if (!*p_block_index) {
3891                 NL_SET_ERR_MSG(extack, "Block number may not be zero");
3892                 return -EINVAL;
3893         }
3894
3895         return 0;
3896 }
3897
3898 int tcf_qevent_init(struct tcf_qevent *qe, struct Qdisc *sch,
3899                     enum flow_block_binder_type binder_type,
3900                     struct nlattr *block_index_attr,
3901                     struct netlink_ext_ack *extack)
3902 {
3903         u32 block_index;
3904         int err;
3905
3906         if (!block_index_attr)
3907                 return 0;
3908
3909         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3910         if (err)
3911                 return err;
3912
3913         qe->info.binder_type = binder_type;
3914         qe->info.chain_head_change = tcf_chain_head_change_dflt;
3915         qe->info.chain_head_change_priv = &qe->filter_chain;
3916         qe->info.block_index = block_index;
3917
3918         return tcf_block_get_ext(&qe->block, sch, &qe->info, extack);
3919 }
3920 EXPORT_SYMBOL(tcf_qevent_init);
3921
3922 void tcf_qevent_destroy(struct tcf_qevent *qe, struct Qdisc *sch)
3923 {
3924         if (qe->info.block_index)
3925                 tcf_block_put_ext(qe->block, sch, &qe->info);
3926 }
3927 EXPORT_SYMBOL(tcf_qevent_destroy);
3928
3929 int tcf_qevent_validate_change(struct tcf_qevent *qe, struct nlattr *block_index_attr,
3930                                struct netlink_ext_ack *extack)
3931 {
3932         u32 block_index;
3933         int err;
3934
3935         if (!block_index_attr)
3936                 return 0;
3937
3938         err = tcf_qevent_parse_block_index(block_index_attr, &block_index, extack);
3939         if (err)
3940                 return err;
3941
3942         /* Bounce newly-configured block or change in block. */
3943         if (block_index != qe->info.block_index) {
3944                 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
3945                 return -EINVAL;
3946         }
3947
3948         return 0;
3949 }
3950 EXPORT_SYMBOL(tcf_qevent_validate_change);
3951
3952 struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
3953                                   struct sk_buff **to_free, int *ret)
3954 {
3955         struct tcf_result cl_res;
3956         struct tcf_proto *fl;
3957
3958         if (!qe->info.block_index)
3959                 return skb;
3960
3961         fl = rcu_dereference_bh(qe->filter_chain);
3962
3963         switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
3964         case TC_ACT_SHOT:
3965                 qdisc_qstats_drop(sch);
3966                 __qdisc_drop(skb, to_free);
3967                 *ret = __NET_XMIT_BYPASS;
3968                 return NULL;
3969         case TC_ACT_STOLEN:
3970         case TC_ACT_QUEUED:
3971         case TC_ACT_TRAP:
3972                 __qdisc_drop(skb, to_free);
3973                 *ret = __NET_XMIT_STOLEN;
3974                 return NULL;
3975         case TC_ACT_REDIRECT:
3976                 skb_do_redirect(skb);
3977                 *ret = __NET_XMIT_STOLEN;
3978                 return NULL;
3979         }
3980
3981         return skb;
3982 }
3983 EXPORT_SYMBOL(tcf_qevent_handle);
3984
3985 int tcf_qevent_dump(struct sk_buff *skb, int attr_name, struct tcf_qevent *qe)
3986 {
3987         if (!qe->info.block_index)
3988                 return 0;
3989         return nla_put_u32(skb, attr_name, qe->info.block_index);
3990 }
3991 EXPORT_SYMBOL(tcf_qevent_dump);
3992 #endif
3993
3994 static __net_init int tcf_net_init(struct net *net)
3995 {
3996         struct tcf_net *tn = net_generic(net, tcf_net_id);
3997
3998         spin_lock_init(&tn->idr_lock);
3999         idr_init(&tn->idr);
4000         return 0;
4001 }
4002
4003 static void __net_exit tcf_net_exit(struct net *net)
4004 {
4005         struct tcf_net *tn = net_generic(net, tcf_net_id);
4006
4007         idr_destroy(&tn->idr);
4008 }
4009
4010 static struct pernet_operations tcf_net_ops = {
4011         .init = tcf_net_init,
4012         .exit = tcf_net_exit,
4013         .id   = &tcf_net_id,
4014         .size = sizeof(struct tcf_net),
4015 };
4016
4017 static int __init tc_filter_init(void)
4018 {
4019         int err;
4020
4021         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
4022         if (!tc_filter_wq)
4023                 return -ENOMEM;
4024
4025         err = register_pernet_subsys(&tcf_net_ops);
4026         if (err)
4027                 goto err_register_pernet_subsys;
4028
4029         xa_init_flags(&tcf_exts_miss_cookies_xa, XA_FLAGS_ALLOC1);
4030
4031         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
4032                       RTNL_FLAG_DOIT_UNLOCKED);
4033         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
4034                       RTNL_FLAG_DOIT_UNLOCKED);
4035         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
4036                       tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
4037         rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
4038         rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
4039         rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
4040                       tc_dump_chain, 0);
4041
4042         return 0;
4043
4044 err_register_pernet_subsys:
4045         destroy_workqueue(tc_filter_wq);
4046         return err;
4047 }
4048
4049 subsys_initcall(tc_filter_init);